Previous Year Paper

RRC Group D Previous Year Paper 32 (Held On: 1 Oct 2018 Shift 3)

Held in 2018

100 questions90 minutes
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CBT (100 questions)

Question 1

Read the statements and identify the logically correct conclusion from the given information.

Statement:

“The pedestrian crossing is few feet away. It is safe to use it, “says a mother to her child.

Conclusions:

I. Pedestrian should use pedestrian crossing for safety.

II. All the children know what is pedestrian crossing.

  1. AOption (a)

    Only conclusion I follows

  2. BOption (b)

    Both I and II follow

  3. COption (c)

    Only conclusion II follows 

  4. DOption (d)

    Neither I nor II follows 

View answer & explanation

Correct answer

Answer: (a)A.

Only conclusion I follows

Why this answer is correct

According to the given information,

Conclusion 1: This follows, because pedestrian crossing is safe.

Conclusion 2: This does not follow, because it is not mentioned that children know what is

pedestrian crossing.

Hence, “only conclusion 1” follows.

Question 2

What is the third proportional to 9 and 12?

  1. AOption (a)

    19

  2. BOption (b)

    16

  3. COption (c)

    18

  4. DOption (d)

    17

View answer & explanation

Correct answer

Answer: (b)B.

16

Why this answer is correct

Shortcut Trick

For two numbers a and b, the third proportional is given by b2 ÷ a.

Here, a = 9 and b = 12.

Third Proportional = (12 × 12) ÷ 9 = 144 ÷ 9 = 16.

∴ The correct answer is 16.

Alternate Method

Given: First number (a) = 9, Second number (b) = 12.

Formula Used: If x is the third proportional to a and b, then a : b :: b : x.

⇒ 9 / 12 = 12 / x

⇒ 9 × x = 12 × 12

⇒ 9x = 144

⇒ x = 144 ÷ 9

⇒ x = 16

∴ The correct answer is 16.

Additional Information

Mean Proportional

The mean proportional between two numbers a and b is calculated as √(a × b).

Fourth Proportional

If four quantities a, b, c, d are in proportion (a:b = c:d), then d is the fourth proportional, calculated as (b × c) ÷ a.

Continued Proportion

Three numbers a, b, c are in continued proportion if a/b = b/c, which implies b2 = ac.

Question 3

Which of the statements is sufficient to answer the question?

Question:

Find the total number of students in a class if the class has some boys and some girls.

Statements:

I. The number of boys in a class is 10.

II. The number of girls in a class is 2 more than the number of boys.

  1. AOption (a)

    Only statement II is sufficient

  2. BOption (b)

    Either statement I or II is sufficient

  3. COption (c)

    Both statements I and II are sufficient 

  4. DOption (d)

    Only statement I is sufficient

View answer & explanation

Correct answer

Answer: (c)C.

Both statements I and II are sufficient 

Why this answer is correct

Shortcut Trick

To find the total number of students, we need both the number of boys and girls.

Statement I gives only the number of boys (10).

Statement II gives the girls relative to boys (Boys + 2).

Neither statement alone provides both values, but combining them gives Boys = 10 and Girls = 12.

∴ The correct answer is Both statements I and II are sufficient.

Alternate Method

Given:

Statement I: Number of boys (B) = 10

Statement II: Number of girls (G) = B + 2

Formula Used:

Total Students (T) = Boys (B) + Girls (G)

Calculations:

⇒ From Statement I: B = 10

⇒ From Statement II: G = B + 2

⇒ Substitute B from I into II: G = 10 + 2 = 12

⇒ Total Students = 10 + 12 = 22

⇒ Since we used information from both statements to find the unique total, both are necessary.

∴ The correct answer is Both statements I and II are sufficient.

Additional Information

Data Sufficiency Rules

In Data Sufficiency, a question is solvable if the given statements provide a unique value. You do not need to calculate the actual answer, only determine if it can be calculated.

Independent vs. Dependent Statements

If one statement depends on a variable defined in another (like Girls depending on Boys), both statements must be analyzed together to find the solution.

Variable Elimination

For n unknown variables, you generally require n independent equations or pieces of information to find a specific solution.

Question 4

In a code language, TURN is written as STQM. What is the code for LIMP?

  1. AOption (a)

    KHLP

  2. BOption (b)

    KHNQ

  3. COption (c)

    KHLO

  4. DOption (d)

    JHLO

View answer & explanation

Correct answer

Answer: (c)C.

KHLO

Why this answer is correct

The pattern followed is,

Similarly,

Hence, “KHLO” is the correct answer.

Question 5

Select the option that is related to the third word on the same basis as the second word is related to the first word.

Magnetic field : Oersted ∷ Power : ?

  1. AOption (a)

    Litre

  2. BOption (b)

    Volt

  3. COption (c)

    Watt

  4. DOption (d)

    Metre

View answer & explanation

Correct answer

Answer: (c)C.

Watt

Why this answer is correct

Oersted  is the intensity of a magnetic field in vacuum.

Similarly,

Watt is the unit of power.

‘Watt’  is related to the third words on the same basis as the second word is related to the first word.

Hence, “watt” is the correct answer.

Question 6

Kalyan is twice as old as his sister and five times younger than his father. After two years their combined age will be 58. How old is Kalyan’s sister now?

  1. AOption (a)

    5

  2. BOption (b)

    4

  3. COption (c)

    6

  4. DOption (d)

    3

View answer & explanation

Correct answer

Answer: (b)B.

4

Why this answer is correct

Let kalyan’s  age be  2x, kalyan’s sister age be x.

Kalyan’s father’ s age is 10x

After two years their combined age will be 58

X + 2 + 2x + 2 + 10x + 2 = 58

13x + 6 = 58

13x = 52

x= 4

x is Kalyan’s sister’s age, which is 4.

Hence, “4” is the correct answer.

Question 7

If east becomes north-east, what will be north become?

  1. AOption (a)

    North-west

  2. BOption (b)

    North-east

  3. COption (c)

    West

  4. DOption (d)

    East

View answer & explanation

Correct answer

Answer: (a)A.

North-west

Why this answer is correct

Drawing diagram according to the given information,

There is a moment of 450 anti clock – wist .

If east becomes, north – east, the north becomes ‘north – west’.

Hence, “north – west” is the correct answer.

Question 8

In 2017, The Government of India announced which of the following schemes to help replace incandescent bulbs with LED bulbs?

  1. AOption (a)

    Deen Dayal Upadhayaya Gram Jyoti Yojana (DDUGJY)

  2. BOption (b)

    Vidyut Shakti Sanrakshan Yojana (vssy)

  3. COption (c)

    Integrated Power Development Scheme (IPDS)

  4. DOption (d)

    Unnat Jyoti by Affordabled LEDs for All (UJALA)

View answer & explanation

Correct answer

Answer: (d)D.

Unnat Jyoti by Affordabled LEDs for All (UJALA)

Why this answer is correct

The correct answer is option 4 i.e Unnat Jyoti by Affordable LEDs for All​ (UJALA).

  • The Government of India announced Unnat Jyoti by Affordable LEDs for All (UJALA) scheme to help replace incandescent bulbs with LED bulbs and promote lightening, enhance awareness on using efficient equipment with less electricity bill and help preserve the environment.
  • The scheme was launched by Prime Minister of India Narendra Modi on 1 May 2015.
  • The scheme comes under the Ministry of Power.
  • In May 2017, the Government of India expanded the LED distribution project to the United Kingdom.
Deen Dayal Upadhayaya Gram Jyoti Yojana (DDUGJY)- Scheme aimed to provide a continuous power supply to rural India. - Launch year: 2015.
Integrated Power Development Scheme (IPDS)- The scheme aimed at Strengthening sub-transmission and distribution networks in the urban areas. - Launched by the Modi Government.

Question 9

3 R # 2  A $ K 5 % T 7 & N Y + X B / L Q @ 1

If the second half of the above series is reversed then using the new series find the missing term

+%2 : /3∷@y3 ∷ @y : ______

  1. AOption (a)

    7XR

  2. BOption (b)

    TB#

  3. COption (c)

    BT#

  4. DOption (d)

    %#K

View answer & explanation

Correct answer

Answer: (b)B.

TB#

Why this answer is correct

Reversing the second half of the series,

3 R # 2  A $ K 5 % T 7 1 @ Q L / B X + Y N &

The pattern followed is,

For +%2 : /$3,

There is a gap of 9 between ‘+’ and ‘%’ and there a gap of 4 between ‘%’ and ‘2’

And,

There is a gap of 9 between ‘/’ and ‘′andthereagapof4between′' and there a gap of 4 between '’ and ‘3’

Similarly,

For @y$: _

There is a gap of 6 between ‘@’ and ‘y’ and there a gap of 13 between ‘y’ and ‘$’

And,

Similarly,

There is a gap of 6 between ‘T’ and ‘B’ and there a gap of 13 between ‘B’ and ‘#’

Hence, “TB#” is the correct answer.

Question 10

Diksha obtained 58% marks in an exam where the maximum marks was 450. She obtained___ marks.

  1. AOption (a)

    290

  2. BOption (b)

    276

  3. COption (c)

    261

  4. DOption (d)

    275.5

View answer & explanation

Correct answer

Answer: (c)C.

261

Why this answer is correct

Shortcut Trick

Marks = 58% of 450

Calculate 50% + 8% of 450

50% of 450 = 225

8% of 450 = 36

Total = 225 + 36 = 261

∴ The correct answer is 261 marks.

Alternate Method

Given:

Maximum Marks = 450

Percentage Obtained = 58%

Formula Used:

Marks Obtained = (Percentage ÷ 100) × Total Marks

⇒ Marks = (58 ÷ 100) × 450

⇒ Marks = 0.58 × 450

⇒ Marks = 58 × 4.5

⇒ Marks = 261

∴ The correct answer is 261 marks.

Additional Information

Percentage Change

Percentage change = (Difference ÷ Original Value) × 100. It measures how much a value has increased or decreased relative to its base.

Fraction to Percentage Conversion

To convert a fraction to a percentage, multiply the fraction by 100. For example, 3/5 = (3/5) × 100 = 60%.

Base Change Property

x% of y is always equal to y% of x. This is useful for easier mental calculations (e.g., 16% of 50 = 50% of 16 = 8).

Question 11

The data shows the information on the number of children vaccinated in the year 2016 in different cities.

If the total number of children vaccinated in the year 2016 is 1,20,000, then how many kids from city ‘B’ were vaccinated?

  1. AOption (a)

    24,000

  2. BOption (b)

    48,000

  3. COption (c)

    12,000

  4. DOption (d)

    36,000

View answer & explanation

Correct answer

Answer: (d)D.

36,000

Why this answer is correct

Given:

Number of children vaccinated = 120000

Calculation:

Percentage of kids from city B who were vaccinated = 30%

∴ Number of kids from city B who were vaccinated = 1,20,000 × 30/100 = 36,000

Question 12

Choose the correct Venn Diagram which represents the given words:

“Utensils, Furniture, Clothes”

  1. AOption (a)

  2. BOption (b)

  3. COption (c)

  4. DOption (d)

View answer & explanation

Correct answer

Answer: (a)A.

Why this answer is correct

Utensils, furniture and clothes are represented separately.

The correct Venn diagram is,

Hence, option 1 is the correct answer.

Question 13

Sindhu can cover a distance of 2023;km20\frac{2}{3};km in 7347\frac{3}{4} hours on foot. How many km per hour does she walk?

  1. AOption (a)

    4 km

  2. BOption (b)

    23km\frac{2}{3}km

  3. COption (c)

    223km2\frac{2}{3}km

  4. DOption (d)

    323km3\frac{2}{3}km

View answer & explanation

Correct answer

Answer: (c)C.

223km2\frac{2}{3}km

Why this answer is correct

Shortcut Trick

Convert mixed fractions to improper fractions: Distance = 62/3 km and Time = 31/4 hours.

Speed = Distance ÷ Time ⇒ (62/3) ÷ (31/4).

Speed = (62/3) × (4/31) = 2 × (4/3) = 8/3 kmph.

8/3 kmph = 2(2/3) kmph.

∴ The correct answer is 2(2)/(3)km.

Alternate Method

Given:

Distance covered by Sindhu = 20(2/3) km

Time taken = 7(3/4) hours

Formula Used:

Speed = Distance ÷ Time

Calculations:

⇒ Distance = 20(2/3) = (20×3 + 2)/3 = 62/3 km

⇒ Time = 7(3/4) = (7×4 + 3)/4 = 31/4 hours

⇒ Speed = (62/3) / (31/4)

⇒ Speed = (62/3) × (4/31)

⇒ Speed = (2 × 4) / 3

⇒ Speed = 8/3 = 2(2/3) kmph

∴ The correct answer is 2(2)/(3)km.

Additional Information

Unit Conversion

To convert km/hr to m/s, multiply the value by 5/18. To convert m/s to km/hr, multiply by 18/5.

Average Speed

Average Speed = Total Distance ÷ Total Time. If distances are equal, Average Speed = 2xy/(x+y).

Question 14

A statement is followed by two arguments. Decide which of the arguments is/are strong with respect to the statement.

Statement:

Too much of pain killer affects the liver.

Arguments:

I. Yes, for all small aches we should avoid taking pain killers.

II. No, when we have the comfort of gulping a tablet; why to beat the pain?

  1. AOption (a)

    Only argument I is strong.

  2. BOption (b)

    Both I and II are strong

  3. COption (c)

    Only argument II is strong

  4. DOption (d)

    Neither I nor II is strong

View answer & explanation

Correct answer

Answer: (a)A.

Only argument I is strong.

Why this answer is correct

According to the given information,

Conclusion 1: This is strong, because pain killers should be avoided for small aches.

Conclusion 2: This is not strong, because taking too many pain killers will affect the liver.

Hence, “only argument 1” is strong.

Question 15

If the simple interest on a certain sum for 1.5 years at 8% p.a. is Rs. 360. Find the compound interest on the same sum for the same rate of interest but double the time?

  1. AOption (a)

    Rs. 778

  2. BOption (b)

    Rs. 778.13

  3. COption (c)

    Rs. 779

  4. DOption (d)

    Rs. 779.13

View answer & explanation

Correct answer

Answer: (d)D.

Rs. 779.13

Why this answer is correct

Shortcut Trick

Effective Simple Interest rate = 1.5 × 8% = 12%

If 12% → ₹360, then 100% (Principal) = (360 ÷ 12) × 100 = ₹3000

For Compound Interest, Time = 1.5 × 2 = 3 years

Effective CI rate for 3 years at 8% = 25.9712%

CI = 3000 × 25.9712% = ₹779.136

∴ The correct answer is ₹779.13.

Alternate Method

Given: Simple Interest (SI) = ₹360, Rate (R) = 8% p.a., Time (T1) = 1.5 years

Formula Used: SI = (P × R × T) ÷ 100 | CI = P[(1 + R/100)n − 1]

⇒ SI = (P × 8 × 1.5) ÷ 100

⇒ 360 = (P × 12) ÷ 100

⇒ Principal (P) = (360 × 100) ÷ 12 = ₹3000

⇒ New Time (n) = 1.5 × 2 = 3 years

⇒ Compound Interest (CI) = 3000 × [(1 + 8/100)3 − 1]

⇒ CI = 3000 × [(1.08)3 − 1]

⇒ CI = 3000 × [1.259712 − 1]

⇒ CI = 3000 × 0.259712 = ₹779.136

∴ The correct answer is ₹779.13.

Additional Information

Effective Rate of Compound Interest

For 3 years at rate R%, effective CI rate = 3R.3R2R3 (using decimal positions for calculations).

Difference between CI and SI

Difference for 2 years = P(R/100)2. Difference for 3 years = P(R/100)2 × (3 + R/100).

Compound Interest Formula

Amount (A) = P(1 + R/100)n, where P is Principal, R is Rate, and n is Time in years.

Question 16

The capital of Jharkhand is _____

  1. AOption (a)

    Hattia

  2. BOption (b)

    Patna

  3. COption (c)

    Ranchi

  4. DOption (d)

    Jamshedpur

View answer & explanation

Correct answer

Answer: (c)C.

Ranchi

Why this answer is correct

The correct answer is option 3 i.e Ranchi.

  • Ranchi is the capital of Indian state Jharkhand.
  • The Jharkhand state was formed on 15 November 2000.
  • The current chief minister of Jharkhand is Hemant Soren.
  • The current Governor of  jharkhand  is Ramesh Bais.
Hattia- Small town and railway station located in Ranchi district, Jharkhand. - National Institute of Foundry and Forge Technology, is situated in Hattia.
Patna- Capital of Bihar. - the ancient name of Patna was Patliputra. - Founded in 490 BCE by the king of Magadha.
Jamshedpur- Famous City located in Jharkhand. - Founded by Jamsetji Tata and was also named after him. - Jamshedpur ranked as the 15th cleanest city in India by Swachh Survekshan 2019.

Question 17

Rathin & Bratin together can complete a piece of work in 12 days. They start the work together but Rathin had to leave 5 days before the work got over. As a result it took a total of 15 days to complete the work. How many days would it have taken Bratin to complete the work by himself?

  1. AOption (a)

    20

  2. BOption (b)

    24

  3. COption (c)

    30

  4. DOption (d)

    28

View answer & explanation

Correct answer

Answer: (c)C.

30

Why this answer is correct

Shortcut Trick

Total time taken = 15 days. Rathin left 5 days before, so Bratin worked alone for the last 5 days.

Rathin & Bratin together worked for 15 − 5 = 10 days.

Work left by both in 2 days (12 − 10) = Work done by Bratin in 5 days.

Efficiency Ratio (R+B) : B = 5 : 2 → Efficiency of B = 2 units, Total Work = 5 × 12 = 60 units.

Time for Bratin = 60 ÷ 2 = 30 days.

∴ The correct answer is 30 days.

Alternate Method

Given: (Rathin + Bratin) can do work in 12 days. Total time taken = 15 days. Rathin left 5 days before completion.

PersonDaysTotal WorkEfficiency
Rathin + Bratin12WW/12
BratinxW/x

Let efficiency of Rathin be R and Bratin be B.

⇒ Total Work = 12 × (R + B)

⇒ According to question: 10 × (R + B) + 5 × B = 12 × (R + B)

⇒ 5B = 2 × (R + B)

⇒ 5B = 2R + 2B

⇒ 3B = 2R → R/B = 3/2

⇒ Let B = 2 and R = 3. Total Work = 12 × (3 + 2) = 60 units.

⇒ Time for Bratin = 60 ÷ 2 = 30 days.

∴ The correct answer is 30 days.

Additional Information

Work Left Before Completion

If a person leaves 'n' days before completion, add their 'n' days of work to the total work and divide by combined efficiency.

Efficiency and Time

Efficiency is inversely proportional to the time taken to complete the work (E ∝ 1/T).

Man-Days Formula

M1D1H1/W1 = M2D2H2/W2, used for comparing work done by different groups.

Question 18

The substances whose odor changes in acidic or basic medium are called ______.

  1. AOption (a)

    Natural indicators

  2. BOption (b)

    Synthetic indicatiors

  3. COption (c)

    Acid-base indicators

  4. DOption (d)

    Olfactory indicators

View answer & explanation

Correct answer

Answer: (d)D.

Olfactory indicators

Why this answer is correct

The correct answer is Olfactory indicators​.

  • The substances whose odour changes in an acidic or basic medium are called olfactory indicators.
  • In an olfactory indicator, smell varies depending on whether it is mixed with an acidic or basic solution.
  • These are mainly used in laboratories to check whether a given solution is a basic or an acidic solution by a process called olfactory titration.
  • Examples: Onion, clove oil, and vanilla extract.
Synthetic indicators- An indicator prepared from artificial substances(Man-made). - Example: Methyl orange, phenolphthalein.
Natural indicators- Indicators obtained from natural sources. - Examples: Turmeric, litmus (obtained from lichen).
Acid-base indicators- Chemicals used to determine whether an aqueous solution is acidic, neutral, or alkaline. - Examples: litmus paper, phenolphthalein, and red cabbage juice.

Question 19

Which of the following statements is/are true/ false about the speed of sound in the different medium at 25° C?

A. In oxygen gas, speed of sound is 316 m/s

B. In water (distilled), the speed of sound is 1498 m/s

  1. AOption (a)

    Only A is true

  2. BOption (b)

    Neither A nor B are trure

  3. COption (c)

    Both A and B are true

  4. DOption (d)

    Only B is true

View answer & explanation

Correct answer

Answer: (c)C.

Both A and B are true

Why this answer is correct

The correct answer is option 3 i.e Both A and B are true.

  • Both statements are true.
  • The speed of sound in oxygen gas at 25°C is 316 m/s.
  • The speed of sound in water (distilled) at 25°C is 1498 m/s.
  • The speed of sound decreases when it passes from solid to gaseous state of a given medium.
  • Sound travels fastest through solids.
  • The speed of sound depends on the medium through which it is travelling and the temperature and pressure of that medium.

Additional Information 

Speed of sound in different media at 25 ºC
StateMediumSpeed of sound (m/s)
SolidSolids Aluminium6420
Nickel6040
Steel5960
Iron5950
Brass4700
Glass (Flint)3980
liquidLiquids Water (Sea)1531
Water (distilled)1498
Ethanol 12071207
Methanol1103
gasGases Hydrogen1284
Helium965
Air346
Oxygen316
Sulfur dioxide213

https://ncert.nic.in/ncerts/l/iesc112.pdf

Question 20

Find the square root of the perfect square made by multiplying 4050 with a least positive integer.

  1. AOption (a)

    80

  2. BOption (b)

    90

  3. COption (c)

    85

  4. DOption (d)

    95

View answer & explanation

Correct answer

Answer: (b)B.

90

Why this answer is correct

Shortcut Trick

Prime factorize 4050: 4050 = 81 × 50 = 81 × 25 × 2.

4050 = 92 × 52 × 21.

To make it a perfect square, multiply by the missing factor 2.

New number = 4050 × 2 = 8100.

Square root = √8100 = 90.

∴ The correct answer is 90.

Alternate Method

Given: Number = 4050.

Step 1: Find the prime factors of 4050.

⇒ 4050 = 2 × 2025

⇒ 4050 = 2 × 3 × 675

⇒ 4050 = 2 × 3 × 3 × 225

⇒ 4050 = 2 × 3 × 3 × 3 × 75

⇒ 4050 = 2 × 3 × 3 × 3 × 3 × 25

⇒ 4050 = 21 × 34 × 52

Step 2: Identify the factor with an odd exponent.

⇒ The factor 2 has an exponent of 1.

⇒ To make it a perfect square, we multiply by 2.

Step 3: Calculate the square root of the resulting number.

⇒ Square root = √(22 × 34 × 52)

⇒ Square root = 2 × 32 × 5

⇒ Square root = 2 × 9 × 5 = 90

∴ The correct answer is 90.

Additional Information

Perfect Square Condition

A number is a perfect square if all the exponents in its prime factorization are even numbers.

Square Root of a Product

The property √(a × b) = √a × √b is used to simplify the calculation of roots after factorization.

Least Positive Integer

To find the least multiplier for a perfect square, multiply the number by the product of all prime factors that have odd powers.

Question 21

Transpiration takes place through the ______.

  1. AOption (a)

    vascular bundles

  2. BOption (b)

    cortex

  3. COption (c)

    stomata

  4. DOption (d)

    epidermis

View answer & explanation

Correct answer

Answer: (c)C.

stomata

Why this answer is correct

The correct answer is option 3 i.e Stomata.

  • Transpiration takes place through the stomata.
  • Stomata is a tiny opening or pore, found in the epidermis of leaves, stems, and other organs, that facilitates gas exchange.
  • Stomata are typically found in plant leaves but can also be found in some stems.
  • The pore is surrounded by a pair of specialized parenchyma called guard cells that are responsible for regulating the size of the stomatal opening.
Vascular bundles- Part of the transport system in vascular plants. - Exists in two forms: xylem and phloem. - Xylem: Transporting water from roots to stems and leaves. - Phloem: Transporting food produced from photosynthesis from leaves to roots and stems.
Cortex- The outer layer of a stem or root in a plant. - Lying below the epidermis but outside the vascular bundles.
Epidermis- Single-layer of cells that cover the leaves, flowers, roots, and stems of plants. - It protects against water loss, regulates gas exchange, absorbs water and mineral nutrients.

Question 22

If L stands for +, M stand for -, N stands for ×, P stands for ÷ then what is the value of 7N12L48P4M6?

  1. AOption (a)

    98

  2. BOption (b)

    90

  3. COption (c)

    94

  4. DOption (d)

    92

View answer & explanation

Correct answer

Answer: (b)B.

90

Why this answer is correct

By decoding given information,

LMNP
Means
+-×÷

 

7N12L48P4M6

7 × 12 + 48 ÷ 4 – 6

Using BODMAS rule,

7 × 12 + 12 – 6

84 + 12 – 6

96 – 6

90

Hence, “90” is the correct answer.

Question 23

The potential difference between the terminals of an electric heater is 60 V when it draws a current of 4 A from the source. What current will the heater draw if the potential difference is increased to 172.5 V? 

  1. AOption (a)

    10 A

  2. BOption (b)

    24 A

  3. COption (c)

    8.5 A

  4. DOption (d)

    11.5 A

View answer & explanation

Correct answer

Answer: (d)D.

11.5 A

Why this answer is correct

The correct answer is option 4 i.e 11.5 A.

Given,

Potential difference(V)= 60 V.

Current (I)= 4 A.

Using ohm's law:

V=I × RV= I\ \times \ R

Resistance (R)= VIV \over I

∴ R=  604=15 Ω{60 \over 4} = 15\ \Omega

If the potential difference is increased to 172.5 V

V= 172.5 V

R= 15 Ω

Current (I)=VR=172.515=11.5 A{V \over R}= {172.5 \over 15}= 11.5 \ A.

∴The heater will draw 11.5 A current if the potential difference is increased to 172.5 V.

Question 24

Name the shuttler who represents the Olympic committee in the Badminton world Federation?

  1. AOption (a)

    Saina Nehwal

  2. BOption (b)

    K Srikanth

  3. COption (c)

    P Gopichand

  4. DOption (d)

    B Sai Praneeth

View answer & explanation

Correct answer

Answer: (a)A.

Saina Nehwal

Why this answer is correct

The correct answer is option 1 i.e Saina Nehwal

  • Saina Nehwal was the shuttler who represented the Olympic committee in the Badminton World Federation.
  • Saina is the only female player from India and overall the second Indian player who attains the world no. 1 ranking after Prakash Padukone.
  • She has represented India three times in the Olympics.
  • Autobiography: Playing to Win: My Life On and Off Court.
  • Saina joined the Bharatiya Janata Party on 29 January 2020.
K Srikanth- Indian badminton player. - He became the best men's singles badminton player in the world in April 2018. - Awards: Padma Shri (2018), Arjuna award (2015).
P Gopichand- Former Indian badminton player. - Presently, Chief National Coach for the Indian Badminton team. - 1st Indian to be honoured with Lifetime award by the Olympics Committee.
B Sai Praneeth- Indian badminton player. - First Indian male shuttler in 36 years to win a bronze medal in the BWF World Championships after Prakash Padukone. - Honoured with the Arjun Award in 2019.

Question 25

The above figure is embedded in any of these four figures. The correct pictures containing the above picture is:

  1. AOption (a)

    C

  2. BOption (b)

    D

  3. COption (c)

    B

  4. DOption (d)

    A

View answer & explanation

Correct answer

Answer: (d)D.

A

Why this answer is correct

The given figure is embedded in,

Hence, option 4 is the correct answer.

Question 26

Choose the best suitable Venn diagram for the following words

“Metal, Gold, Platinum”

  1. AOption (a)

  2. BOption (b)

  3. COption (c)

  4. DOption (d)

View answer & explanation

Correct answer

Answer: (a)A.

Why this answer is correct

Gold and platinum are metals.

The correct Venn diagram is,

Hence, option 1 is the correct answer.

Question 27

A Person borrowed Rs. 32,000 at a yearly 9% simple interest and deposited the same amount in a bank at a yearly compound interest of 10%. What is the gain in rupees at the end of 3 years?

  1. AOption (a)

    Rs. 926

  2. BOption (b)

    Rs. 1,940

  3. COption (c)

    Rs. 2,904

  4. DOption (d)

    Rs. 1,952

View answer & explanation

Correct answer

Answer: (d)D.

Rs. 1,952

Why this answer is correct

Shortcut Trick

Net Simple Interest rate for 3 years = 9% × 3 = 27%.

Net Compound Interest rate for 3 years at 10% = 33.1%.

Difference in interest percentage = 33.1% − 27% = 6.1%.

Total gain = 6.1% of ₹32,000 = 0.061 × 32,000 = ₹1,952.

∴ The correct answer is ₹1,952.

Alternate Method

Given: Principal (P) = ₹32,000, SI rate (R1) = 9%, CI rate (R2) = 10%, Time (T) = 3 years.

Formula Used: SI = (P × R × T) / 100 | CI = P × [(1 + R/100)T − 1]

Calculations:

⇒ Simple Interest (SI) = (32,000 × 9 × 3) / 100

⇒ SI = 320 × 27 = ₹8,640

⇒ Compound Interest (CI) = 32,000 × [(1 + 10/100)3 − 1]

⇒ CI = 32,000 × [(1.1)3 − 1] = 32,000 × [1.331 − 1]

⇒ CI = 32,000 × 0.331 = ₹10,592

⇒ Total Gain = CI − SI = 10,592 − 8,640

⇒ Gain = ₹1,952

∴ The correct answer is ₹1,952.

Additional Information

Effective Rate for 10% Compound Interest

For 2 years, effective CI rate = 10 + 10 + (10 × 10)/100 = 21%. For 3 years, it is 21 + 10 + (21 × 10)/100 = 33.1%.

Difference between CI and SI

When rates are equal (R), the difference for 2 years is P(R/100)2 and for 3 years is P(R/100)2 × (3 + R/100).

Simple Interest Nature

Simple Interest remains constant every year because it is always calculated on the original Principal amount.

Question 28

Which of the following states that "Properties of elements are a periodic function of their atomic number"?

  1. AOption (a)

    Dobereiner's triads

  2. BOption (b)

    Modern periodic law

  3. COption (c)

    Newlands's law of octaves

  4. DOption (d)

    Mendeleev's periodic law

View answer & explanation

Correct answer

Answer: (b)B.

Modern periodic law

Why this answer is correct

The correct answer is option 2 i.e Modern periodic law.

  • Modern periodic law states that "Properties of elements are a periodic function of their atomic number".
  • Modern periodic law was proposed by Henry Moseley in 1913.
  • Mendeleev's periodic law is slightly different from Moseley's, it states that "Properties of the elements are periodic functions of their atomic mass".
  • Mendeleev's periodic law was proposed by Dmitri Ivanovich Mendeleev.
Dobereiner's triads- States that the atomic mass of the middle element of a triad is the arithmetic mean of the atomic masses of the other two elements. - Example: Triad of lithium, sodium,  and potassium.
Newlands's law of octaves- States that when the elements are arranged in the increasing order of their atomic masses every eighth element has similar properties. - Proposed by John Newlands.

Question 29

The relation between potential difference (V) and current (I) was discovered by:

  1. AOption (a)

    Pascal

  2. BOption (b)

    Tesla

  3. COption (c)

    Newton

  4. DOption (d)

    Ohm 

View answer & explanation

Correct answer

Answer: (d)D.

Ohm 

Why this answer is correct

The correct answer is option 4 i.e Ohm.

  • The relation between the potential difference (V) and current (I) was discovered by Georg Ohm.
  • The law was named after the scientist who discovered it and hence it is known as ohm's law.
  • Ohm's law states that the current through a conductor between two points is directly proportional to the voltage across the two points.
  • V=I × RV= I\ \times \ R
Pascal- The pascal (Pa) is the SI derived unit of pressure. - The unit, named after Blaise Pascal.
Newton- Newton is the SI unit of force. - The unit Named after Isaac Newton.
Tesla- Tesla is the unit of magnetic induction. - Named in honour of Nikola Tesla.

Question 30

Out of the four option figures, three are similar in a certain manner. However, one figure is NOT like the other three.

Select the figure which is different from the rest.

  1. AOption (a)

    C

  2. BOption (b)

    B

  3. COption (c)

    D

  4. DOption (d)

    A

View answer & explanation

Correct answer

Answer: (c)C.

D

Why this answer is correct

The pattern followed is,

In figure A, there is a triangle inside a triangle, in figure B there is a circle inside a circle and in figure

C there is a square inside a square.

But,

In figure D, there is a rhombus inside a hexagon, both the figures are not same.

Hence, figure D is different from the rest.

Question 31

A car, while moving, is facing a wind from the opposite direction. The work done by the wind on the car will be ______.

  1. AOption (a)

    Infinity

  2. BOption (b)

    Positive

  3. COption (c)

    Zero

  4. DOption (d)

    Negative

View answer & explanation

Correct answer

Answer: (d)D.

Negative

Why this answer is correct

The correct answer is option 4 i.e Negative.

  • The work done by the wind on the car while it is blowing, from the opposite direction of the car will be negative.
  • Work is the product of force and displacement.
  • The SI unit of work is the joule (J).
  • The work done by a force can be either positive or negative or zero.
Positive Work- Work done is Positive, If applied force displaces the object in the same direction of the force.
Negative Work- Work done is Negative, If applied force displaces the object in the opposite direction of the force.
Zero Work- If the directions of force and the displacement are perpendicular to each other, the work done by the force on the object is zero.

Question 32

The SI unit of power is______.

  1. AOption (a)

    Erg

  2. BOption (b)

    Kilowatt

  3. COption (c)

    Joule

  4. DOption (d)

    Watt

View answer & explanation

Correct answer

Answer: (d)D.

Watt

Why this answer is correct

The correct answer is option 4 i.e Watt.

Key Points

  • The SI unit of power is Watt.
  • The Watt is named after James Watt.
  • Power is the amount of energy transferred per unit time.
  • 1 watt (W) = 1.00 joules per second (J/sec).
  • Power is a scalar quantity.

Additional Information

Erg- Unit of energy(not an SI unit). - Equal to 10−7 joules (100 nJ). - Its name is derived from ergon, a Greek word meaning work or task.
Kilowatt- Unit of electric power. - One kilowatt (kW) is equal to 1000 watts (W).
Joule- SI-derived unit of energy. - Named after the English physicist James Prescott Joule.

Question 33

Person A, B and C can complete a task together in 81 days. A and B can completed the same task together in 97.2 days. B and C can complete the same task together in 162 days. In how many days can B alone complete the task?

  1. AOption (a)

    243

  2. BOption (b)

    225

  3. COption (c)

    261

  4. DOption (d)

    234

View answer & explanation

Correct answer

Answer: (a)A.

243

Why this answer is correct

Shortcut Trick

Total Work = LCM(81, 97.2, 162) = 486 units.

Efficiency of (A+B+C) = 486 ÷ 81 = 6 units/day.

Efficiency of (A+B) = 486 ÷ 97.2 = 5 units/day.

Efficiency of (B+C) = 486 ÷ 162 = 3 units/day.

Efficiency of B = (A+B) + (B+C) − (A+B+C) = 5 + 3 − 6 = 2 units/day.

Time taken by B = 486 ÷ 2 = 243 days.

∴ The correct answer is 243 days.

Alternate Method

Given: (A+B+C) = 81 days, (A+B) = 97.2 days, (B+C) = 162 days.

Formula Used: Efficiency = Total Work ÷ Time; Time = Total Work ÷ Efficiency.

PersonDaysTotal WorkEfficiency
A + B + C814866
A + B97.25
B + C1623

⇒ Efficiency of C = Efficiency(A+B+C) − Efficiency(A+B)

⇒ Efficiency of C = 6 − 5 = 1 unit/day.

⇒ Efficiency of B = Efficiency(B+C) − Efficiency(C)

⇒ Efficiency of B = 3 − 1 = 2 units/day.

⇒ Time taken by B = 486 ÷ 2 = 243 days.

∴ The correct answer is 243 days.

Additional Information

Total Work Assumption

Total work is always assumed to be the Least Common Multiple (LCM) of the number of days taken by the individuals to simplify efficiency calculations.

Inverse Relation of Time and Efficiency

Efficiency is inversely proportional to the time taken to complete a work. If time increases, efficiency decreases and vice versa.

Additive Nature of Efficiency

When people work together, their individual efficiencies are added to get the combined rate of work per day.

Question 34

There are 10 protons and 17 neutrons in the nucleus of an element. What is its mass number?

  1. AOption (a)

    27

  2. BOption (b)

    7

  3. COption (c)

    17

  4. DOption (d)

    10

View answer & explanation

Correct answer

Answer: (a)A.

27

Why this answer is correct

The correct answer is option 1 i.e 27

  • Mass number is 27.
  • The mass number is the total number of protons and neutrons in an atomic nucleus.
  • The number of protons = 10.
  • Number of neutrons = 17.
  • Mass number = Number of protons + Number of neutrons = 10 + 17 =  27.

Question 35

Select the option that is related to the third word on the same basis as the second word is related to the first word.

Sound : Ear ∷ Scent :

  1. AOption (a)

    Feel

  2. BOption (b)

    Think

  3. COption (c)

    Smell

  4. DOption (d)

    Nose

View answer & explanation

Correct answer

Answer: (d)D.

Nose

Why this answer is correct

Sound is heard with the help of ears.

Similarly,

Scent is smelled with the help of nose.

‘Nose’ is related to the third word on the same basis as the second word is related to the first word.

Hence, “nose” is the correct answer.

Question 36

If the vulgar fraction of 0.41‾0.\overline {41}  is given by 41999……9(n;times)\frac{{41}}{{999 \ldots \ldots 9\left( {n;times} \right)}}then find the value of n?

  1. AOption (a)

    4

  2. BOption (b)

    3

  3. COption (c)

    2

  4. DOption (d)

    1

View answer & explanation

Correct answer

Answer: (c)C.

2

Why this answer is correct

Calculation:

Let n = 0.41

n = 0.41         ---- (i)

n = 0.4141

Two digits are repeated after the decimal point,

So we multiply both sides by 100.

100n = 41.41          ---- (ii)

From (ii) - (i) 

⇒ 100n - n = 41.41 - 0.41

⇒ 99n = 41

⇒ n = 41/99

∴ The value of n {999……9(ntimes)} is 2.

Question 37

Bratin is now 18 years old, whereas his cousin is 7 years old. After how many years will Bertin’s age be 1.5 times that of his cousin?

  1. AOption (a)

    15

  2. BOption (b)

    16

  3. COption (c)

    13

  4. DOption (d)

    14

View answer & explanation

Correct answer

Answer: (a)A.

15

Why this answer is correct

According to the given information,

Bratin’ s age is 18 years

His cousin’ s age is 7 years

Verifying the given options,

Option 1→ 15 years

Bratin’ s age after 15 years is 33

His cousin’s age after 15 years is 22

22 × 1.5 = 33

Option 2 → 16 years

Bratin’ s age after 16 years is 34

His cousin’s age after 16 years is 23

23 × 1.5 is not equal to 34

Option 3 → 13 years

Bratin’ s age after 13 years is 31

His cousin’s age after 13 years is 20

20 × 1.5 is not equal to 31

Option 4 → 14 years

Bratin’ s age after 14 years is 32

His cousin’s age after 14 years is 21

21 × 1.5 is not equal to 32

Hence, “15 years” is the correct answer.

Question 38

Choose the odd one from among the given figures

  1. AOption (a)

    A

  2. BOption (b)

    D

  3. COption (c)

    C

  4. DOption (d)

    B

View answer & explanation

Correct answer

Answer: (d)D.

B

Why this answer is correct

The pattern followed is,

In figures A, C and D the arrow mark is present on the sides of the triangle.

Whereas,

In figure B, the arrow is at the base of the triangle.

Hence, figure B is the odd one.

Question 39

The British made English the medium of instruction in India in ____

  1. AOption (a)

    1835

  2. BOption (b)

    1857

  3. COption (c)

    1855

  4. DOption (d)

    1833

View answer & explanation

Correct answer

Answer: (a)A.

1835

Why this answer is correct

The correct answer is option 1 i.e 1835.

  • The British made English the medium of instruction in India in 1835.
  • Macaulay's minute of 1835 leads to the inclusion of the English language as the medium of instruction in government schools and colleges in India.
  • Lord William Bentinck was the governor-general of India during Macaulay's minute of 1835.
  • Macaulay has a major role in the introduction of Western concepts to education in India.
  • The famous Infiltration theory was introduced by Macaulay.
  • As a part of developments in the education sector, the Elphinstone College (Bombay) and the Calcutta Medical College were established. in 1835.

Question 40

How is Srilekha’s brother’s only sister’s father’s sister related to her?

  1. AOption (a)

    Paternal Aunt

  2. BOption (b)

    Sister

  3. COption (c)

    Mother

  4. DOption (d)

    Grandmother

View answer & explanation

Correct answer

Answer: (a)A.

Paternal Aunt

Why this answer is correct

Drawing the family tree,

Srilekha’s brother’s only sister’s father’s sister is the paternal aunt to her.

Hence, “paternal aunt” is the correct answer.

Question 41

A fraction when added to 173\frac{{17}}{3} gives 4. What is the said fraction?

  1. AOption (a)

    −11-\frac{{1}}{1}

  2. BOption (b)

    −123-1\frac{{2}}{3}

  3. COption (c)

    92\frac{{9}}{2}

  4. DOption (d)

    23\frac{{2}}{3}

View answer & explanation

Correct answer

Answer: (b)B.

−123-1\frac{{2}}{3}

Why this answer is correct

Given:

A fraction when added to 173\frac{{17}}{3} gives 4.

Concept:

Whenever there is a need of taking a fraction, take it as ‘x/1’ as this will reduce calculation.

Example: Find the fraction which is equal to the reciprocal of 2.

Suppose, fraction = x/1

x/1 = ½ ⇒ x = ½ or Fraction = ½

Calculation:

Let the fraction be x

According to the question

x + 17/3 = 4

⇒ x = 4 - 17/3

⇒ x = (12 - 17)/3

⇒ x = -5/3

⇒ x −123-1\frac{{2}}{3}

∴ The fraction −123-1\frac{{2}}{3}

Question 42

Which of the following statements is/are true/false?

A. An acid which is completely ionized into ions and produces a large number of H+ ions. For example HCl, H2 SO4, HNO3

B. An acid which is partially ionized in water and produces less number of H+ ions. For example CH3COOH, H2CO3, H2SO2

  1. AOption (a)

    Both A and B are true

  2. BOption (b)

    Only B is true

  3. COption (c)

    Both A and B are false

  4. DOption (d)

    Only A is true

View answer & explanation

Correct answer

Answer: (a)A.

Both A and B are true

Why this answer is correct

The correct answer is option 1 i.e Both A and B are true.

  • Both statements are true.
  • An acid or base's strength refers to its degree of ionization.
  • Strong acids completely dissociate into their ions in water.
  • The strong acids are hydrochloric acid (HCl), sulfuric acid(H2SO4, hydrobromic acid, and nitric acid(HNO3).
  • Weak acids only partially dissociate into their ions in water.
  • Most organic acids are weak acids.
  • The examples of these acids are Acetic acid(CH3COOH), Carbonic acid (H2CO3), Sulfoxylic acid (H2SO2).

Question 43

Who received the prestigious Florence Nightingale Award from the former President Pranab Mukherjee in 2017?

  1. AOption (a)

    Krishna Kumari

  2. BOption (b)

    Jaya Lakshmi

  3. COption (c)

    Devi Kumari

  4. DOption (d)

    Kavitha

View answer & explanation

Correct answer

Answer: (a)A.

Krishna Kumari

Why this answer is correct

The correct answer is option 1 i.e Krishna Kumari.

  • Krishna Kumari, Odisha nurse has bagged the prestigious Florence Nightingale award 2017.
  • She received the award from former President Pranab Mukherjee at a function at the Rashtrapati Bhawan in New Delhi on the occasion of International Nurses Day.
  • Florence Nightingale was an English reformer and the founder of modern nursing.
  • The Florence Nightingale Awards are given for nursing professionals, as a mark of recognition for the meritorious services of nurses.
  • Award was instituted by the Health ministry in 1973.
  • The National Florence Nightingale Award 2019 was presented by President Ram Nath Kovind to Lini Puthussery, the nurse from Kerala who died due to the Nipah virus.

Question 44

The SI unit of pressure is ______.

  1. AOption (a)

    Newton

  2. BOption (b)

    Ohm

  3. COption (c)

    Pascal

  4. DOption (d)

    Dyne

View answer & explanation

Correct answer

Answer: (c)C.

Pascal

Why this answer is correct

​The correct answer is option 3 i.e Pascal.

  • Pascal (Pa) is the SI unit of pressure.
  • The unit of pressure is named after scientist Blaise Pascal.
  • The pressure is the force applied perpendicular to the surface of an object per unit area over which that force is distributed.
  • The Barometer is a scientific instrument that is used to measure air pressure.
Ohm- Ohm is the SI derived unit of electrical resistance. - The unit Ohm is named after Georg Simon Ohm. - Symbol: Ω.
Newton- Newton is the SI unit of force. - The symbol of the newton is 'N'. - Newton is also used as the unit of weight. - Named after Isaac Newton, who developed the laws of motion.
Dyne- Dyne is the unit of force in the centimetre-gram-second (CGS) system of physical units. - One dyne = 10−5 N.

Question 45

Let α, β be the roots of ax2 + bx + c = 0; γ, δ be the roots of px2 + qx + r = 0 ;& D1 , D2 the respective discriminants of these equations. If α, β, γ, δ are in A.P. Then find the value of D1 : D2

  1. AOption (a)

    a2p2\frac{{{a^2}}}{{{p^2}}}

  2. BOption (b)

    a2b2\frac{{{a^2}}}{{{b^2}}}

  3. COption (c)

    b2q2\frac{{{b^2}}}{{{q^2}}}

  4. DOption (d)

    c2r2\frac{{{c^2}}}{{{r^2}}}

View answer & explanation

Correct answer

Answer: (a)A.

a2p2\frac{{{a^2}}}{{{p^2}}}

Why this answer is correct

Shortcut Trick

The difference of roots for any quadratic equation Ax2 + Bx + C = 0 is given by √D/|A|.

Since α, β, γ, δ are in Arithmetic Progression (A.P.), the difference between consecutive roots is the same.

⇒ |β − α| = |δ − γ| = d (common difference).

⇒ √D1/|a| = √D2/|p|

⇒ D1/a2 = D2/p2 ⇒ D1 : D2 = a2 : p2.

∴ The correct answer is a2/p2.

Alternate Method

Given: ax2 + bx + c = 0 has roots α, β and px2 + qx + r = 0 has roots γ, δ.

Formula Used: (α − β)2 = (α + β)2 − 4αβ = D/a2.

⇒ For ax2 + bx + c = 0, sum (α + β) = −b/a and product αβ = c/a.

⇒ (α − β)2 = (−b/a)2 − 4(c/a) = (b2 − 4ac)/a2 = D1/a2.

⇒ Similarly for px2 + qx + r = 0, (γ − δ)2 = (q2 − 4pr)/p2 = D2/p2.

⇒ Since α, β, γ, δ form an Arithmetic Progression, let the common difference be d.

⇒ β − α = d and δ − γ = d.

⇒ d2 = D1/a2 and d2 = D2/p2.

⇒ Equating both: D1/a2 = D2/p2.

⇒ D1/D2 = a2/p2.

∴ The correct answer is a2/p2.

Additional Information

Discriminant and Nature of Roots

The discriminant (D = b2 − 4ac) defines the roots: If D > 0, roots are real and unequal; if D = 0, roots are real and equal; if D < 0, roots are complex conjugates.

Difference of Roots

The absolute difference between roots is |α − β| = √D / |a|, which is useful when roots are related by a constant gap.

Arithmetic Progression (A.P.) Properties

In an A.P., any four terms x1, x2, x3, x4 satisfy the condition that x2 − x1 = x4 − x3 = d, where d is the common difference.

Question 46

In triangle ABC, AD ⊥ BC and AO is the bisector of ∠BAC. If ∠ABC = 65° and ∠ACB = 231∘2,23\frac{{1^\circ }}{2}, then ∠DAO is ____ (in degrees)

  1. AOption (a)

    201∘420\frac{{1^\circ }}{4}

  2. BOption (b)

    201∘520\frac{{1^\circ}}{5}

  3. COption (c)

    201∘220\frac{{1^\circ }}{2}

  4. DOption (d)

    203∘420\frac{{3^\circ }}{4}

View answer & explanation

Correct answer

Answer: (d)D.

203∘420\frac{{3^\circ }}{4}

Why this answer is correct

Shortcut Trick

The angle between the altitude and the angle bisector of the vertical angle is half the positive difference of the base angles.

∠DAO = 1/2 × |∠ABC − ∠ACB|

∠DAO = 1/2 × (65° − 23.5°) = 1/2 × 41.5° = 20.75°

20.75° = 20° + 3/4° = 203°/4

∴ The correct answer is 203°/4.

Alternate Method

Given: ∠B = 65°, ∠C = 23.5°, AD ⊥ BC, AO is bisector of ∠A.

Formula Used: Angle sum property of triangle = 180°.

⇒ In ΔABC, ∠BAC = 180° − (65° + 23.5°) = 180° − 88.5° = 91.5°

⇒ Since AO is the angle bisector, ∠BAO = 91.5° ÷ 2 = 45.75°

⇒ In right-angled ΔABD, ∠BAD = 90° − ∠B = 90° − 65° = 25°

⇒ ∠DAO = ∠BAO − ∠BAD = 45.75° − 25° = 20.75°

⇒ 20.75° = 20 + 75/100 = 20 + 3/4 = 203°/4

∴ The correct answer is 203°/4.

Additional Information

Internal Angle Bisector Theorem

In a triangle, the internal bisector of an angle divides the opposite side in the ratio of the sides containing the angle: AB/AC = BD/CD.

Altitude of a Triangle

The altitude is a line segment through a vertex and perpendicular to the opposite side. The three altitudes intersect at the orthocenter.

Angle Sum Property

The sum of the interior angles of any triangle is always 180°. For a right-angled triangle, the sum of the two acute angles is 90°.

Question 47

Find the mirror image of the given figure if the mirror is placed at line MN.

  1. AOption (a)

    D

  2. BOption (b)

    B

  3. COption (c)

    A

  4. DOption (d)

    C

View answer & explanation

Correct answer

Answer: (d)D.

C

Why this answer is correct

The mirror image of the given figure if the mirror is placed at line MN is,

Hence, option 4 is the correct answer.

Question 48

_________ was the founder of the Lodi Dynasty.

  1. AOption (a)

    Sultan Ibrahim

  2. BOption (b)

    Ala-ud-din Lodi

  3. COption (c)

    Ibranhim Lodi

  4. DOption (d)

    Bahlul Lodi

View answer & explanation

Correct answer

Answer: (d)D.

Bahlul Lodi

Why this answer is correct

​The correct answer is Bahlul Lodi.

Key Points

  • The Lodi dynasty was founded by Bahlul Khan Lodi.
  • The Lodi dynasty was an Afghan dynasty.
  • The Lodi dynasty was the last dynasty in Delhi Sultanate, ruled from 1451 to 1526.
  • Sikandar Lodi was the son of Bahlul founded Agra in 1504.
  • Ibrahim Lodi was the son of Sikandar Lodi and he was the last Lodi Sultan of Delhi.
  • The Mughal emperor Babur defeated and killed Ibrahim Lodi in the Battle of Panipat, in 1526.
  • The death of Ibrahim Lodi ended the 320 years long Delhi Sultanate, and the Mughal Empire replaced it.

Question 49

The Indian Women's hockey team won the Asia Cup 2017 by defeating which coutry?

  1. AOption (a)

    Germany

  2. BOption (b)

    South Korea

  3. COption (c)

    China

  4. DOption (d)

    Japan

View answer & explanation

Correct answer

Answer: (c)C.

China

Why this answer is correct

The correct answer is option 3 i.e China.

  • Indian Women's hockey team won the Asia Cup 2017 by defeating China.
  • Host country: Japan.
  • This is India's second title.
  • The tournament organized by the Asian Hockey Federation.
  • Headquarters of the Asian Hockey Federation: Kuala Lumpur, Malaysia.
  • President of the Asian Hockey Federation: Al-Sultan Abdullah Sultan Ahmad Shah.
  • South Korea has won the most titles(3).
  • 2017 Men's Hockey Asia Cup: India won the third title after defeating Malaysia.

Question 50

In a class there were 18 boys and some girls. In a test the mean score obtained by the boys was 12 while that obtained by the girls was 14. If the overall average was 13.1, what was the total number of students in the class?

  1. AOption (a)

    38

  2. BOption (b)

    44

  3. COption (c)

    42

  4. DOption (d)

    40

View answer & explanation

Correct answer

Answer: (d)D.

40

Why this answer is correct

Shortcut Trick

Ratio of Boys to Girls using the Alligation method:

(Girls Mean − Total Mean) : (Total Mean − Boys Mean)

⇒ (14 − 13.1) : (13.1 − 12) = 0.9 : 1.1 = 9 : 11

Given: 9 units = 18 boys ⇒ 1 unit = 2

Total students = (9 + 11) units = 20 units × 2 = 40 students

∴ The correct answer is 40 students.

Alternate Method

Given:

Number of Boys (nb) = 18

Mean score of Boys (xb) = 12

Mean score of Girls (xg) = 14

Overall Average (xtotal) = 13.1

Formula Used:

Overall Average = [(nb × xb) + (ng × xg)] ÷ (nb + ng)

Let the number of Girls be G.

⇒ 13.1 = [(18 × 12) + (G × 14)] ÷ (18 + G)

⇒ 13.1 × (18 + G) = 216 + 14G

⇒ 235.8 + 13.1G = 216 + 14G

⇒ 14G − 13.1G = 235.8 − 216

⇒ 0.9G = 19.8

⇒ G = 19.8 ÷ 0.9 = 22

⇒ Total Students = 18 + 22 = 40

∴ The correct answer is 40 students.

Additional Information

Weighted Average

It calculates the average of a combined set where each group has a different number of observations: Avg = (n1A1 + n2A2) ÷ (n1 + n2).

Alligation Rule

The ratio of the quantities is inversely proportional to the differences of their individual averages from the target mean: n1/n2 = (A2 − Am) / (Am − A1).

Mean Properties

The sum of deviations of all observations from the mean is always zero. The overall mean always lies between the lowest and highest group means.

Question 51

Aanya and Manya are standing facing each other. Anya is facing North-West. Which direction in Manya facing with respect to Anya?

  1. AOption (a)

    South- West

  2. BOption (b)

    North- East

  3. COption (c)

    South- East

  4. DOption (d)

    North- West

View answer & explanation

Correct answer

Answer: (c)C.

South- East

Why this answer is correct

Drawing diagram according to the given information,

Manya is south – east with respect to Anya.

Hence, “south – east" is the correct answer.

Question 52

A person walks 25\frac{2}{5}th of the total distance and covers one-third of the remaining distance by bus. What is the fraction of the remaining distance to be covered?

  1. AOption (a)

    35\frac{3}{5}

  2. BOption (b)

    25\frac{2}{5}

  3. COption (c)

    715\frac{7}{15}

  4. DOption (d)

    15\frac{1}{5}

View answer & explanation

Correct answer

Answer: (b)B.

25\frac{2}{5}

Why this answer is correct

Formula:

Distance remaining to be covered = Total distance - Distance covered

Calculation:

Let total distance be x km.

Distance covered by the person by walking = x × 2/5 = 2x/5

⇒ Remaining distance = x - 2x/5 = 3x/5

1/3rd part of remaining distance covered by bus then

Distance covered by the bus = 3x/5 × 1/3 = x/5

<br>

Now final remaining distance

⇒ Remaining distance = x - 2x/5 - x/5 = 2x/5

∴ Required fraction = 2x/5 × 1/x = 2/5

Question 53

Who won the Best Actress Award at the 64th National Film Awards in 2017?

  1. AOption (a)

    Sonam Kapoor

  2. BOption (b)

    Taapsee Pannu

  3. COption (c)

    Anushka Sharma

  4. DOption (d)

    Surabhi Lakshmi

View answer & explanation

Correct answer

Answer: (d)D.

Surabhi Lakshmi

Why this answer is correct

The correct answer is option 4 i.e Surabhi Lakshmi.

  • Surabhi Lakshmi won the Best Actress Award at the 64th National Film Awards in 2017.
  • Surabhi won this award for her role in the Malayalam film Minnaminungu.
  • Award was presented by former Indian President Pranab Mukherjee.
  • Best Feature Film: Kaasav (Marathi).
  • Best Actor: Akshay Kumar (Hindi film Rustom).
CategoryWinner
Best Feature FilmHellaro(Gujarati)
Best ActorAyushman Khurrana and Vicky Kaushal
Best ActressKeerthy Suresh
Best Film on Other Social IssuesPad man

Question 54

India's first World Heritage City Status was accorded to which of the following city by UNESCO?

  1. AOption (a)

    Hyderabad

  2. BOption (b)

    Hampi

  3. COption (c)

    Jaipur

  4. DOption (d)

    Ahmedabad

View answer & explanation

Correct answer

Answer: (d)D.

Ahmedabad

Why this answer is correct

The correct answer is option 4 i.e Ahmedabad.

  • Ahmedabad is India's first World Heritage City recognised by UNESCO.
  • As per the official records, Ahmedabad is the first Indian city honoured with World Heritage City Status by UNESCO (Third city in Asia, after Bhaktapur(Nepal) and Galle(Srilanka)).
  • UNESCO stands for United Nations Educational Scientific and Cultural Organization.
  • Headquarters of UNESCO: Paris, France.
  • Director-General of UNESCO: Audrey Azoulay.
  • Ahmedabad city was founded by Sultan Ahmed Shah.
  • Recently, the Jaipur was declared as India's second city in UNESCO World Heritage Site on July 6, 2019.
Hyderabad- Capital of Telangana - The Charminar constructed in 1591 is located in Hyderabad. - Hyderabad was founded by the Quṭb Shahi sultans of Golconda. - Recently the Telangana government declared 2020 as the Artificial Intelligence year.
Hampi- UNESCO World Heritage Site located in Karnataka, - Hampi was the capital of the Vijayanagara Empire in the 14th century. - Situated on the banks of the Tungabhadra River. - Hampi-Vijayanagara was the world's second-largest medieval-era city after Beijing
Jaipur- Capital of Rajasthan. - Also known as the Pink City. - Founded in 1727 by the Rajput ruler Jai Singh II. - On 6 July 2019, UNESCO World Heritage Committee inscribed Jaipur the ‘Pink City of India’ among its World Heritage Sites.

Question 55

Which of the following pairs do not have the same SI unit?

  1. AOption (a)

    Displacement and distance

  2. BOption (b)

    Force and pressure

  3. COption (c)

    work and energy

  4. DOption (d)

    Speed and velocity

View answer & explanation

Correct answer

Answer: (b)B.

Force and pressure

Why this answer is correct

The correct answer is option 2 i.e Force and Pressure.

Key Points

  • Force and pressure do not have the same SI unit.
  • SI unit of force is the newton(N).
  • SI unit of pressure is the pascal(Pa).
  • The SI unit of distance and displacement is the meter (m).
  • The SI unit of energy and work is the joule (J).
  • The SI unit of speed and velocity is meter per second (m/s).

Question 56

Read the following statement and the arguments that follow. Decide which of the arguments is strong.

Statement:

Young entrepreneurs should be encouraged.

Arguments:

I. Yes. It helps in the industrial development of the country and reduces burden on the employment market.

II. No, they are not experienced and may make losses.

  1. AOption (a)

    Only argument I is strong

  2. BOption (b)

    Either argument I or II is strong

  3. COption (c)

    Neither argument I nor II is strong

  4. DOption (d)

    Only argument II is strong

View answer & explanation

Correct answer

Answer: (a)A.

Only argument I is strong

Why this answer is correct

According to the given information,

Argument 1:  This is strong, because young entrepreneurs help in the development of the country.

Argument 2: This is not strong, because nothing is mentioned about losses in the statement and

young entrepreneurs reduces burden on the employment market.

Hence, “only argument 1” is strong.

Question 57

The atomic mass of aluminum is 27. The number of moles present in 81 grams of aluminum is _____.

  1. AOption (a)

    4

  2. BOption (b)

    5

  3. COption (c)

    2

  4. DOption (d)

    3

View answer & explanation

Correct answer

Answer: (d)D.

3

Why this answer is correct

The correct answer is option 4 i.e. 3.

The number of moles present in 81 grams of aluminium is 3 moles.

Number of moles=Mass of substanceMass of one mole{{Number \ of\ moles}={Mass\ of \ substance \over Mass\ of\ one\ mole}}

Mass of substance= 81 grams

Mass of one mole(molar mass) aluminum= 27.

The number of moles=8127=3{81 \over 27}= 3 moles.

Question 58

What is the SI unit of speed?

  1. AOption (a)

    m/s

  2. BOption (b)

    km/h

  3. COption (c)

    m/minute

  4. DOption (d)

    km/s

View answer & explanation

Correct answer

Answer: (a)A.

m/s

Why this answer is correct

The correct answer is option 1 i.e m/s.

  • The SI unit of speed is meter per second(m/s).
  • The speed of an object is the magnitude of the change of its position.
  • Speed is a scalar quantity.
  • The most common unit of speed in everyday usage is kilometre per hour (km/h).
  • For air and marine travel the knot is commonly used as the unit of speed.

Question 59

You are given question and two statement. Identify which of the statement is/are necessary to answer the question.

How is Rajesh related to Vijay?

Statement:

I. Rajesh is the only son of Vijay’s mother-in-law.

II. Verma is Rajesh’s only sister.

  1. AOption (a)

    Data in I alone is sufficient

  2. BOption (b)

    Data in both I and II together are not sufficient

  3. COption (c)

    Data either in I alone or II alone are sufficient 

  4. DOption (d)

    Data in II alone is sufficient 

View answer & explanation

Correct answer

Answer: (a)A.

Data in I alone is sufficient

Why this answer is correct

According to the given statements,

Statement 1: Rajesh is the only son of Vijay’s mother-in-law.

Rajesh is the brother – in – law of Vijay.

Statement 2: Verma is Rajesh’s only sister.

From, statement 1, we can say that Rajesh is the brother – in – law of Vijay.

Hence, “data in 1 alone” is sufficient.

Question 60

A girl saw a clock when it was 3 am. The clock losses 16 minutes per day. What will be the actual time when she sees the clock on the 4th day at 8 pm?

  1. AOption (a)

    9 : 15 pm

  2. BOption (b)

    9 : 00 pm

  3. COption (c)

    8 : 30 pm

  4. DOption (d)

    9 : 30 pm

View answer & explanation

Correct answer

Answer: (b)B.

9 : 00 pm

Why this answer is correct

Total hours when clock on the 4th day at 8 pm = 24 + 24 + 24 + 17 =  89 hours

Clock losses in 24 hours = 16 minutes

Clock losses in 1 hour =  1624 {\ {16} \over 24} minutes

In 89 hours clock losses =  1624×89 {\ {16} \over 24} × 89 =  23×89 {\ {2} \over 3} × 89 =  1783 {\ {178} \over 3}  = 59. 33 minutes ≈ 1 hr

So Actual time  when girl sees the clock on the 4th day at 8 pm = 8 + 1 = 9 pm

Hence, "9.00 pm" is the correct answer.

Question 61

Choose the correct picture that replaces the (?) symbol above with the below given options:

  1. AOption (a)

    A

  2. BOption (b)

    D

  3. COption (c)

    C

  4. DOption (d)

    B

View answer & explanation

Correct answer

Answer: (c)C.

C

Why this answer is correct

The picture that replaces the (?) symbol is,

Hence, option 3 is the correct answer.

Question 62

An object moving with a uniform velocity of 4ms-1 possesses kinetic energy of 120 J. Find the mass of the object.

  1. AOption (a)

    15 N

  2. BOption (b)

    15 W

  3. COption (c)

    15 Kg

  4. DOption (d)

    15 Pa

View answer & explanation

Correct answer

Answer: (c)C.

15 Kg

Why this answer is correct

The correct answer is option 3 i.e 15 Kg.

Given,

Velocity (v) = 4ms-1.

Kinetic energy = 120 J.

Using the equation of kinetic energy,

Kinetic energy= 12mv2{1 \over 2}{mv^2}

∴ Mass(m) = 2×Kinetic Energyv22 \times Kinetic \ Energy \over v^2(= {2 \times 120 \over16 }\)= 15 Kg.

Hence the mass of the object is 15 Kg.

Question 63

Which of the following is not a noble gas?

  1. AOption (a)

    oganesson

  2. BOption (b)

    Argon

  3. COption (c)

    Xenon

  4. DOption (d)

    Chlorine

View answer & explanation

Correct answer

Answer: (d)D.

Chlorine

Why this answer is correct

The correct answer is option 4 i.e Chlorine.

Key Points

  • Among the options, all except Chlorine, are noble gasses
  • Chlorine belongs to the halogen family.
  • The naturally occurring noble gases are helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and, radon (Rn).
  • Noble gases belong to group 18 in the periodic table.
  • Oganesson is a synthetic chemical element with the symbol Og and atomic number 118.
Argon- Atomic number: 18. - Third-most abundant gas in the Earth's atmosphere. - Argon is produced industrially by the fractional distillation of liquid air. - Argon is commonly used to fill incandescent light bulbs.
Xenon- Atomic number: 54. - Xenon was discovered by the William Ramsay and Morris Travers

Question 64

Who was conferred with the Best Director Award in the 64th National Film Awards?

  1. AOption (a)

    Rajesh Mapuskar

  2. BOption (b)

    Srijit Mukherji

  3. COption (c)

    Anurag Basu

  4. DOption (d)

    Nitesh Tiwari

View answer & explanation

Correct answer

Answer: (a)A.

Rajesh Mapuskar

Why this answer is correct

The correct answer is option 1 i.e Rajesh Mapuskar.

  • The Famous Indian director Rajesh Mapuskar was conferred with the Best Director Award in the 64th National Film Awards.
  • Rajesh Mapuskar was awarded for directing a Marathi film named Ventilator.
  • Best Film Friendly State (2017): Uttar Pradesh.
  • Best Film Friendly State (2019): Uttarakhand.
  • The Best Director in 66th National Film Awards (2019): Aditya Dhar.
  • Aditya Dhar was awarded for directing a Hindi film named Uri: The Surgical Strike.

Question 65

Pointing to a man, Pankaj(boy) said, “He is the brother of my uncle’s daughter”. How is this man related to Pankaj?

  1. AOption (a)

    Nephew

  2. BOption (b)

    Cousin

  3. COption (c)

    Uncle

  4. DOption (d)

    Son

View answer & explanation

Correct answer

Answer: (b)B.

Cousin

Why this answer is correct

Drawing the diagram,

The man is the cousin to Pankaj.

Hence, “cousin” is the correct answer

Question 66

If 10 sec2x - 9 tan2x = 13 and 0° ≤ x 90°, then x = _____.

  1. AOption (a)

    30°

  2. BOption (b)

    45°

  3. COption (c)

    60° 

  4. DOption (d)

    90°

View answer & explanation

Correct answer

Answer: (c)C.

60° 

Why this answer is correct

Shortcut Trick

Use the identity sec2x = 1 + tan2x.

10(1 + tan2x) − 9 tan2x = 13

10 + 10 tan2x − 9 tan2x = 13

tan2x = 3 ⇒ tan x = √3

∴ The correct answer is 60°.

Alternate Method

Given: 10 sec2x − 9 tan2x = 13

Formula Used: sec2x − tan2x = 1

⇒ 10 sec2x − 9 tan2x = 13

⇒ (9 sec2x − 9 tan2x) + sec2x = 13

⇒ 9(sec2x − tan2x) + sec2x = 13

⇒ 9(1) + sec2x = 13

⇒ sec2x = 13 − 9

⇒ sec2x = 4

⇒ sec x = 2

⇒ x = cos−1(1/2) = 60°

∴ The correct answer is 60°.

Additional Information

Trigonometric Identities

Fundamental Pythagorean identities include sin2x + cos2x = 1, 1 + tan2x = sec2x, and 1 + cot2x = cosec2x.

Specific Angles

Common values for tan x: tan 30° = 1/√3, tan 45° = 1, tan 60° = √3.

Reciprocal Relations

sec x = 1/cos x, cosec x = 1/sin x, and cot x = 1/tan x.

Question 67

Which of the fractions given below is not equal to 59\frac{5}{9}?

  1. AOption (a)

    105198\frac{105}{198}

  2. BOption (b)

    80144\frac{80}{144}

  3. COption (c)

    4072\frac{40}{72}

  4. DOption (d)

    2545\frac{25}{45}

View answer & explanation

Correct answer

Answer: (a)A.

105198\frac{105}{198}

Why this answer is correct

Concept:

Deduce each fraction into its simplest form and then check for its value.

Example: a/b

If ‘a’ is divided by ‘c’ and it gives 5 as quotient then ‘b’ on division by ‘c’ should give 9 as quotient to make a/b = 5/9.

Calculation:

Option 1: 105/198

Write the fraction in the simplest form so, divide the numerator and denominator of the fraction by 3.

⇒ 35/66

Option 2: 80/144

Write the fraction in the simplest form so, divide the numerator and denominator of the fraction by 16.

⇒ 5/9

Option 3: 40/72

Write the fraction in the simplest form so, divide the numerator and denominator of the fraction by 8.

⇒ 5/9

Option 4: 25/45

Write the fraction in the simplest form so, divide the numerator and denominator of the fraction by 5.

⇒ 5/9

∴ 105/198 cannot ne written in the form of 5/9.

Question 68

20 men can finish a certain work in 10 days, where as it takes 12 women to finish it in 10 days. If 15 men and 6 women undertake to complete the work, how many days will they take to complete it?

  1. AOption (a)

    8 days

  2. BOption (b)

    10 days

  3. COption (c)

    6 days

  4. DOption (d)

    4 days

View answer & explanation

Correct answer

Answer: (a)A.

8 days

Why this answer is correct

Shortcut Trick

Efficiency ratio of Men to Women: 20M × 10 = 12W × 10 ⇒ 5M = 3W ⇒ M/W = 3/5.

Total Work = 20 × 3 × 10 = 600 units.

Efficiency of (15M + 6W) = (15 × 3) + (6 × 5) = 45 + 30 = 75 units/day.

Time taken = 600 ÷ 75 = 8 days.

∴ The correct answer is 8 days.

Alternate Method

Given: 20 men can do work in 10 days; 12 women can do work in 10 days.

Formula Used: Total Work = Number of persons × Efficiency × Days

PersonDaysTotal WorkEfficiency
20 Men1012012
12 Women1012

⇒ Efficiency of 20 men = 120 ÷ 10 = 12 units/day

⇒ Efficiency of 1 man = 12 ÷ 20 = 0.6 units/day

⇒ Efficiency of 12 women = 120 ÷ 10 = 12 units/day

⇒ Efficiency of 1 woman = 12 ÷ 12 = 1 unit/day

⇒ Total Efficiency of (15 men + 6 women) = (15 × 0.6) + (6 × 1)

⇒ Total Efficiency = 9 + 6 = 15 units/day

⇒ Days required = Total Work ÷ Total Efficiency = 120 ÷ 15

⇒ Days required = 8 days

∴ The correct answer is 8 days.

Additional Information

Work Equivalence Formula

M1D1H1/W1 = M2D2H2/W2 where M is number of workers, D is days, H is hours and W is work done.

Efficiency and Time

Efficiency is inversely proportional to the time taken to complete a task when the work remains constant.

Pipes & Cisterns

Similar to time and work, the rate of filling a tank is its efficiency, and total capacity is the total work.

Question 69

When light travels form a denser medium to a rare medium, what is the effect on its speed?

  1. AOption (a)

    Increases 

  2. BOption (b)

    No change

  3. COption (c)

    Decreases

  4. DOption (d)

    Decreases and the increases

View answer & explanation

Correct answer

Answer: (a)A.

Increases 

Why this answer is correct

The correct answer is option 1 i.e Increases.

  • When light travels from a denser medium to a rare medium speed of light will increase.
  • The refraction of light is the phenomenon of bend or change the direction of light rays when it passes from one medium to another.
  • When light travels from denser to rarer medium, it bends away from the normal.
  • According to Snell's Law: sin⁡θ2sin⁡θ1=ν2ν1=n1n2{\sin \theta_2 \over \sin \theta_1}= {\nu_2 \over \nu_1}={n_1 \over n_2}
  • Denser medium has a greater refractive index(n1) when compared to an optically rarer medium (n2).
  • According to Snell's law, speed will Increase while travelling from a denser medium to rarer, i.e.(v1>v2).

Question 70

_______ is the state flower of Jharkhand.

  1. AOption (a)

    Lotus

  2. BOption (b)

    Rohira

  3. COption (c)

    Orchid

  4. DOption (d)

    Palash

View answer & explanation

Correct answer

Answer: (d)D.

Palash

Why this answer is correct

The correct answer is option 4 i.e Palash.

  • Palash is the state flower of Jharkhand and Uttar Pradesh.
  • State animal of Jharkhand: Indian elephant.
  • State bird of Jharkhand: Asian Koel.
  • Jharkhand state was formed on 15 November 2000.
  • Chief Minister of Jharkhand: Hemant Soren.
  • Rohira is the state flower of Rajasthan.
  • Orchid is the state flower of Arunachal Pradesh.
  • Lotus is the National Flower of India and the state flower of Karnataka.

Question 71

Find the missing letter in the series:

Y, W, U, S ?, O

  1. AOption (a)

    N

  2. BOption (b)

    T

  3. COption (c)

    R

  4. DOption (d)

    Q

View answer & explanation

Correct answer

Answer: (d)D.

Q

Why this answer is correct

The pattern followed is,

Hence, “Q” is the correct answer.

Question 72

Choose the correct mirror image for the following figure.

  1. AOption (a)

  2. BOption (b)

  3. COption (c)

  4. DOption (d)

View answer & explanation

Correct answer

Answer: (a)A.

Why this answer is correct

The mirror image of the given image is,

Hence, option 1 is the correct answer.

Question 73

In which of the following phenomena can many plants be grown from one parent in disease-free conditions?

  1. AOption (a)

    Sexual reproduction

  2. BOption (b)

    Tissue culture

  3. COption (c)

    Spore formation

  4. DOption (d)

    Regeneration

View answer & explanation

Correct answer

Answer: (b)B.

Tissue culture

Why this answer is correct

The correct answer is Tissue culture.

Key Points

  • Tissue culture is the phenomenon that many plants are grown from one parent in disease-free conditions.
  • The production of plants by the method of tissue culture is also known as micropropagation
  • This technique is being used increasingly for the production of ornamental plants like orchids, dahlia, carnation, chrysanthemum, etc.
  • The new plants produced by tissue culture are disease-free is an advantage of this technique.
Sexual reproduction- Reproduction involves two parents and produces offspring that are genetically unique. - In human reproduction, each cell contains 46 chromosomes in 23 pairs. - Plant reproduction can be accomplished by sexual or asexual reproduction.
Spore formation- This occurs when a plant produces tiny spores and propagates through them. - Fungi like Rhizopus, Mucor, etc., are examples of spore formation.
Regeneration- Regeneration is the ability of an organism to regrow its lost parts. - When a lizard loses its tail and then grows it back, this is an example of regeneration.

Question 74

Read the following statements and the conclusions that follow. Decide which of the two conclusions follow from the given statements.

Statements:

  1. All the cots are hotels.
  2. All hotels are sheets.

Conclusions:

  1. Some cots are not sheets.
  2. Some sheets are cots.
  1. AOption (a)

    Both conclusions 1 and 2 follow

  2. BOption (b)

    Only conclusion 2 follows

  3. COption (c)

    Either conclusion 1 or 2 follows 

  4. DOption (d)

    Only conclusion 1 follows 

View answer & explanation

Correct answer

Answer: (b)B.

Only conclusion 2 follows

Why this answer is correct

Drawing the Venn diagram,

Conclusion 1: Some cots are not sheets → False (This is definitely false)

Conclusion 2:Some sheets are cots → True (This is definitely true)

Hence, “only conclusion 2” follows.

Question 75

Choose the best suitable Venn diagram for the following words:

Amphibians, Tortoise, Crocodile

  1. AOption (a)

  2. BOption (b)

  3. COption (c)

  4. DOption (d)

View answer & explanation

Correct answer

Answer: (d)D.

Why this answer is correct

Tortoise and Crocodile are generally classified into reptiles but they don't have any relation with Amphibians.

The correct Venn diagram is,

Hence, "Option 4" is the correct answer.

Important Points

  1. Crocodile can live both on land as well as water but it is not an amphibian. Crocodiles are very similar to amphibians but they are not termed under amphibians. In fact, they are a part of the reptile family. 2. Tortoises are exclusively land animals. Most other turtles live in the water much of the time, but not tortoises.
  2. Reptiles are born with lungs, typically lay their eggs on dry land, and have scaly skin. Most amphibians are born with gills but later develop lungs, typically lay their eggs in water, and have thin, moist skin (without scales).

Crocodiles lay their eggs on the land unlike the amphibians.

Question 76

Which mobile application has N. Chandrababu Naidu, the Andhra Pradesh chief Minister, launched at the Collectors conference in Vijayawada?

  1. AOption (a)

    'People First' mobile application

  2. BOption (b)

    'People Safe' mobile application

  3. COption (c)

    'People Friend' mobile application

  4. DOption (d)

    'People Help' mobile application

View answer & explanation

Correct answer

Answer: (a)A.

'People First' mobile application

Why this answer is correct

The correct answer is option 1 i.e People First' mobile application.

  • N. Chandrababu Naidu, the Andhra Pradesh former Chief Minister, has launched ‘People First’ mobile application at the Collectors’ conference in Vijayawada.
  • As the name mentions(People First' mobile application), the application will "empower citizens with real-time governance".
  • Andhra Pradesh has the second-longest coastline after Gujarat (Longest in south India).
  • Andhra Pradesh is the first state formed on linguistic basis in India.
  • Governor of Andhra Pradesh: Biswabhusan Harichandan.
  • Chief Minister of Andhra Pradesh: Y. S. Jaganmohan Reddy.

Question 77

The _______ System transports fluids from one place to another.

  1. AOption (a)

    respiratiory

  2. BOption (b)

    vascular

  3. COption (c)

    nervous

  4. DOption (d)

    excretory

View answer & explanation

Correct answer

Answer: (b)B.

vascular

Why this answer is correct

The correct answer is option 2 i.e Vascular

  • The vascular system transports fluids from one place to another.
  • The plant vascular system helps to deliver various resources to the different plant organs and provides mechanical support.
  • Xylem tissue helps for the transportation of water and minerals to the leaves.
  • Phloem tissue helps for the transportation of food from the leaves to different parts of the plant.
Respiratory system- The important system in the plant/human body, the place where gas exchange happens. - The respiratory system consists of the lungs, pharynx, larynx, trachea, and bronchi.
Nervous system- The nervous system is responsible for the control of the body. - The nervous system consists of the brain, spinal cord, sensory organs, and all of the nerves that connect these organs with the rest of the body.
Excretory system- The system that performs the function of excretion, the bodily process of discharging wastes. - Organs involving in excretion are kidneys, large intestine, liver, skin, and lungs.

Question 78

Which of the following tissues is composed of mainly dead cells?

  1. AOption (a)

    Parenchyma

  2. BOption (b)

    Collenchyma

  3. COption (c)

    Aerenchyma

  4. DOption (d)

    Xylem

View answer & explanation

Correct answer

Answer: (d)D.

Xylem

Why this answer is correct

The correct answer is option 4 i.e Xylem.

  • Xylem tissues are composed of mainly dead cells.
  • Xylem is one of the transport tissues in vascular plants.
  • Transportation of water from roots to stems and leaves is the major function of xylem.
  • The term xylem was first used by Carl Nägeli in 1858.
  • Xylem vessels are a long straight chain made of long-dead cells known as vessel elements.
Parenchyma- Composed of living cells - Parenchyma tissue converts sugar into insoluble starch and stores it for future use.
Collenchyma- Simple permanent tissue found in plants. - Present in the mesophyll of leaves that contain chloroplast. - Almost completely absent in monocots.
Aerenchyma- Present in leaves, stems, and roots of the plants - Aerenchyma is richly found in Hydrophytes. - Helps for the transportation of oxygen and reduce cellular oxygen demand in plants

Question 79

Fill the missing number for the series form the given options:

8, 11, 16, 23, 32, ?

  1. AOption (a)

    40

  2. BOption (b)

    43

  3. COption (c)

    46

  4. DOption (d)

    42

View answer & explanation

Correct answer

Answer: (b)B.

43

Why this answer is correct

The pattern followed is,

Hence, “43” is the correct answer.

Question 80

Who is the Chief Minister of Uttarakhand who was elected in 2017?

  1. AOption (a)

    Satpal Maharaj

  2. BOption (b)

    Harak Sigh Rawat

  3. COption (c)

    Trivendra Singh Rawat

  4. DOption (d)

    Prakash Pant

View answer & explanation

Correct answer

Answer: (c)C.

Trivendra Singh Rawat

Why this answer is correct

The correct answer is option 3 i.e Trivendra Singh Rawat.

  • Trivendra Singh Rawat is the Chief Minister of Uttarakhand who was elected in 2017.
  • He was elected from the assembly constituency of Doiwala, In 2017
  • Governor of Uttarakhand: Baby Rani Maurya.
  • Statehood of Uttarakhand: 9 November 2000.
  • Uttarakhand is often referred to as the "Devabhumi" (Land of the Gods).
  • On June 8, 2020, Uttarakhand declared Gairsain as the new summer capital (Winter capital: Dehradun).

Question 81

Aluminium metal is extracted only by:

  1. AOption (a)

    Electrolysis

  2. BOption (b)

    Calcination

  3. COption (c)

    Reduction

  4. DOption (d)

    Oxidation

View answer & explanation

Correct answer

Answer: (a)A.

Electrolysis

Why this answer is correct

The correct answer is option 1 i.e Electrolysis.

  • Aluminium metal can be extracted only by Electrolysis.
  • Aluminium is more reactive than carbon so it must be extracted from its compounds using electrolysis
  • The atomic number of aluminium is 13.
  • Third most abundant element and also the most abundant metal on earth crust.
  • Bauxite is the ore of aluminium.
Calcination- Calcination is a process in which the carbonate ores are converted into oxides in order to obtain the metal. - This process takes place in the absence or limited amount of oxygen.
Reduction- The chemical reaction that involves the gaining of electrons.
Oxidation- This occurs when a reactant loses electrons during the reaction.

Question 82

Halogens contains______.

  1. AOption (a)

    2 gases, two liquids and 1 solid

  2. BOption (b)

    2 gases and 3 solids

  3. COption (c)

    2 gases, one liquid and 2 solids

  4. DOption (d)

    3 gases and 3 solids

View answer & explanation

Correct answer

Answer: (c)C.

2 gases, one liquid and 2 solids

Why this answer is correct

The correct answer is option 3 i.e 2 gases, one liquid, and 2 solids.

  • Halogens contain 2 gases, one liquid, and 2 solids.
  • Halogens are elements of group 17 in the periodic table consisting of five elements: fluorine (F), chlorine (Cl), bromine (Br), iodine (I), and astatine (At).
  • Fluorine and chlorine are gases.
  • Bromine is liquid.
  • Iodine and astatine are solids.
  • Because of their great reactivity, the free halogen elements are not found in nature.

Question 83

A statement is followed by two arguments. Decide which of the argument is/are strong with respect to the statement.

Statement:

Should income tax be abolished in developed countries?

Arguments:

  1. Yes, it will motivate to earn more.
  2. No, people must learn to share their wealth for the betterment of other people.
  1. AOption (a)

    Either argument 1 or 2 is strong

  2. BOption (b)

    Only argument 1 is strong

  3. COption (c)

    Neither 1 nor 2 is strong

  4. DOption (d)

    Only argument 2 is strong

View answer & explanation

Correct answer

Answer: (d)D.

Only argument 2 is strong

Why this answer is correct

According to the given information,

Argument 1: This is not strong, because nothing about earnings is given in the statement.

Argument 2: This is strong, because people must learn to share their wealth for the betterment of

other people.

Hence, “only argument 2” is strong.

Question 84

A solution contains 32 g of common salt in 320 g of water. Calculate the concentration in terms of mass by mass percentage of the solution.

  1. AOption (a)

    9.09%

  2. BOption (b)

    13.05%

  3. COption (c)

    9.09 g

  4. DOption (d)

    8.84%

View answer & explanation

Correct answer

Answer: (a)A.

9.09%

Why this answer is correct

The correct answer is option 1 i.e 9.09%.

Mass of common salt (solute)=32 g

Mass of water =320 g.

Mass of solution= Mass of common salt (solute) + Mass of water = 32+320 = 352.

Using the equation:

Concentration of solution= Mass of common salt(solute)mass of solution×100{Mass\ of\ common\ salt (solute) \over mass\ of\ solution}{\times 100}

Concentration of solution=32352×100=9.09%{32 \over 352} \times 100= 9.09 \%

The concentration of the solution is 9.09%.

Question 85

In diamond, each carbon atom is bonded to:

  1. AOption (a)

    two other carbon atoms

  2. BOption (b)

    three other carbon atoms

  3. COption (c)

    four other carbon atoms

  4. DOption (d)

    five other carbon atoms

View answer & explanation

Correct answer

Answer: (c)C.

four other carbon atoms

Why this answer is correct

The correct answer is option 3 i.e Four other carbon atoms.

  • In a diamond, each carbon atom is bonded to four other carbon atoms.
  • Carbon in diamond is covalently bonded due to its non-metallic character.
  • Diamond is the solid form of carbon.
  • Diamond is the hardest naturally occurring substance found on Earth
  • Diamond and graphite are the most common allotropes of pure carbon.
  • India has only one active diamond mine which is located at Panna, in Madhya Pradesh.

Question 86

India's first bullet train is proposed to run between ____.

  1. AOption (a)

    Surat and Mumbai

  2. BOption (b)

    Ahmedabad and Mumbai

  3. COption (c)

    Vadodara and Mumbai

  4. DOption (d)

    Vapi and Mumbai

View answer & explanation

Correct answer

Answer: (b)B.

Ahmedabad and Mumbai

Why this answer is correct

The correct answer is Ahmedabad and Mumbai.

  • India's first bullet train is proposed to run between Ahmedabad and Mumbai.
  • The train will cover the distance of over 508 km from Sabarmati (Gujarat) to Bandra (Mumbai, Maharashtra)
  • Indian Prime Minister Narendra Modi and Japanese Prime Minister Shinzo Abe laid the foundation stone for the project in Ahmedabad, Gujarat on 14 September 2017.
  • The Proposed date for the first run is on 15 August 2022 on the occasion of India's 75th Independence day (Recently advanced by year from the earlier deadline).
  • This project is a joint venture between Indian Railways and Japan’s Shinkansen Technology.
  • India’s second bullet train proposed from Delhi to Amritsar.

Question 87

Amoeba, Paramecium and Bacteria undergo:

  1. AOption (a)

    Sexual reproduction

  2. BOption (b)

    budding

  3. COption (c)

    binary fission

  4. DOption (d)

    multiple fission

View answer & explanation

Correct answer

Answer: (c)C.

binary fission

Why this answer is correct

The correct answer is option 3 i.e binary fission.

  • Amoeba, Paramecium, and Bacteria use binary fission as a means of propagation.
  • Binary fission is an asexual mode of reproduction.
  • In binary fission, The parent organism divide to form 2 new organism.
  • Bacteria is the most common example for the binary fission.
  • The simultaneous occurring of DNA replication and segregation is an important feature if binary fission.
Multiple fission- Process of asexual reproduction. - Many daughter cells are produced from the parent cell. - sporozoans and algae are examples of multiple fission.
Sexual reproduction- Production of a new organism from two parents using their sex cells or gametes. - Sexual reproduction is the most common mode of reproduction in eukaryotes, such as animals, fungi, and plants.
Budding- Budding is the formation of a bud from an organism and the bud is capable of developing into a new individual. - Hydra and yeast are examples of budding.

Question 88

If x = a (sinθ + cosθ) and y = b (sinθ - cosθ) then (x2/ a2) + (y2/b2) = ?

  1. AOption (a)

    3

  2. BOption (b)

    1

  3. COption (c)

    4

  4. DOption (d)

    2

View answer & explanation

Correct answer

Answer: (d)D.

2

Why this answer is correct

Shortcut Trick

Put θ = 90° in the given equations.

x = a(sin 90° + cos 90°) = a(1 + 0) = a ⇒ x/a = 1

y = b(sin 90° − cos 90°) = b(1 − 0) = b ⇒ y/b = 1

(x2/a2) + (y2/b2) = 12 + 12 = 2

∴ The correct answer is 2.

Alternate Method

Given: x = a(sinθ + cosθ) and y = b(sinθ − cosθ)

Formula Used: (m + n)2 + (m − n)2 = 2(m2 + n2) and sin2θ + cos2θ = 1

⇒ x/a = sinθ + cosθ

⇒ x2/a2 = (sinθ + cosθ)2 = sin2θ + cos2θ + 2sinθcosθ

⇒ y/b = sinθ − cosθ

⇒ y2/b2 = (sinθ − cosθ)2 = sin2θ + cos2θ − 2sinθcosθ

⇒ (x2/a2) + (y2/b2) = (sin2θ + cos2θ + 2sinθcosθ) + (sin2θ + cos2θ − 2sinθcosθ)

⇒ (x2/a2) + (y2/b2) = 2(sin2θ + cos2θ) = 2(1) = 2

∴ The correct answer is 2.

Additional Information

Trigonometric Identities

The three fundamental identities are sin2θ + cos2θ = 1, 1 + tan2θ = sec2θ, and 1 + cot2θ = cosec2θ.

Algebraic Expansion

The square of a binomial sum and difference is (a ± b)2 = a2 + b2 ± 2ab.

Question 89

Choose the correct pictures that fit the blank place

  1. AOption (a)

    D

  2. BOption (b)

    C

  3. COption (c)

    A

  4. DOption (d)

    B

View answer & explanation

Correct answer

Answer: (b)B.

C

Why this answer is correct

The pattern followed is,

There are three figures in each row circle, triangle and square.

In the first row, the inside symbol is a multiplication symbol.

In the second row, it is a Addition symbol and in the third row it is a line.

The picture that correctly fits is,

Hence, option 2 is the correct answer.

Question 90

The Asia-Africa-Europe (AAE-1) submarine cable system, the world's longest 100-Gbps submarine cable system was launched by ____.

  1. AOption (a)

    Bharti Airtel

  2. BOption (b)

    Reliance Jio

  3. COption (c)

    Idea Cellular

  4. DOption (d)

    Vodafone

View answer & explanation

Correct answer

Answer: (b)B.

Reliance Jio

Why this answer is correct

The correct answer is option 2 i.e Reliance Jio

  • Reliance Jio launches the Asia-Africa-Europe (AAE-1) submarine cable system.
  • This is World’s Longest 100Gbps Submarine Cable System Measuring 25,000 Kms.
  • A submarine cable system is a cable system that consists of telecom and internet cables, which are laid on the seabed between land-based stations.
  • The cable system will be laid from Marseille, France to Hong Kong.
  • This project was initiated by China Unicom in 2011.

Question 91

Which one the following is the equation for Position - Time relation?

  1. AOption (a)

    s = ut + 1/2 at2

  2. BOption (b)

    V = u + at

  3. COption (c)

    U = v + at

  4. DOption (d)

    2as = v2 - u2

View answer & explanation

Correct answer

Answer: (a)A.

s = ut + 1/2 at2

Why this answer is correct

The correct answer is option 1 i.e s=ut+12at2{s={ut}+{1\over 2}{at^2}}

s=ut+12at2{s={ut}+{1\over 2}{at^2}}  is the equation for Position - Time relation.

This is the second equation of motion.

Equation is used to calculate the distance travelled by a body in time (t), with initial velocity (u) and acceleration (a).

s ⟶positions \ \longrightarrow position

u ⟶initial velocityu \ \longrightarrow initial \ velocity

t ⟶timet \ \longrightarrow time

a ⟶accelerationa \ \longrightarrow acceleration

V = u + atEquation for Velocity - Time relation
V2 = u2 + 2asEquation for Velocity-Position relation

Question 92

In January 2018, who was appointed as the official brand ambassador of Sikkim?

  1. AOption (a)

    A. R. Rahman

  2. BOption (b)

    Sania Mirza

  3. COption (c)

    Bhaichung Bhutia

  4. DOption (d)

    Mary Kom

View answer & explanation

Correct answer

Answer: (a)A.

A. R. Rahman

Why this answer is correct

The correct answer is option 1 i.e A. R. Rahman.

  • A. R. Rahman was appointed as the official brand ambassador of Sikkim in January 2018.
  • A. R. Rahman is an Indian composer, singer, and music producer.
  • Sikkim is the least populous and second smallest among the Indian states.
  • Governor of Sikkim: Ganga Prasad.
  • Chief Minister of Sikkim: Prem Singh Tamang.
Sania Mirza- Indian professional tennis player. - She has won six Grand Slam titles in her career. - Brand ambassador of Telangana.
Bhaichung Bhutia- Former Indian professional footballer. - He is often nicknamed the Sikkimese Sniper. - He unsuccessfully contested the 2014 Lok Sabha elections from the Darjeeling constituency.
Mary Kom- Indian Olympic boxer and incumbent Member of Parliament, Rajya Sabha. - Ranked as No. 1 AIBA World Women's Ranking Light Flyweight category. - First Indian woman boxer to win gold at the 2018 Commonwealth Games.

Question 93

€1156 was divided between two people in the ratio 13 : 21. The one who got the larger share received €_____.

  1. AOption (a)

    782

  2. BOption (b)

    714

  3. COption (c)

    680

  4. DOption (d)

    748

View answer & explanation

Correct answer

Answer: (b)B.

714

Why this answer is correct

Shortcut Trick

Total ratio units = 13 + 21 = 34 units.

Value of 34 units = €1156.

Value of 1 unit = 1156 ÷ 34 = €34.

Larger share (21 units) = 21 × 34 = €714.

∴ The correct answer is €714.

Alternate Method

Given: Total amount = €1156, Ratio = 13 : 21.

Formula: Share of larger portion = (Larger Ratio ÷ Sum of Ratios) × Total Amount

⇒ Sum of ratio parts = 13 + 21 = 34

⇒ Larger share = (21 ÷ 34) × 1156

⇒ Larger share = 21 × (1156 ÷ 34)

⇒ Larger share = 21 × 34

⇒ Larger share = €714

∴ The correct answer is €714.

Additional Information

Ratio and Proportion

A ratio indicates how many times one number contains another. If a quantity Q is divided in ratio a : b, the shares are [a/(a+b)]×Q and [b/(a+b)]×Q.

Unitary Method in Ratios

Find the value of one unit by dividing the total value by the sum of ratio parts, then multiply by the specific part required.

Difference between Shares

The difference between shares can be found directly by (b − a)/(a + b) × Total Amount.

Question 94

Which country had hosted the FIFA under 17 world cup in the year 2017?

  1. AOption (a)

    India

  2. BOption (b)

    England

  3. COption (c)

    Australia

  4. DOption (d)

    Pakistan

View answer & explanation

Correct answer

Answer: (a)A.

India

Why this answer is correct

The correct answer is option 1 i.e India.

  • India hosted the FIFA under 17 world cup in the year 2017.
  • This is the first time India has hosted a FIFA tournament.
  • The mascot was "Kheleo".
  • England won the U-17 World Cup for the first time and Spain became the runner-up.
  • FIFA was founded in 1904.
  • President of FIFA: Gianni Infantino.
  • FIFA Founded at Paris, France.

Question 95

Divide 1,380 among A, B and C, so that A gets 5 times of C and 3 times of B. 

  1. AOption (a)

    A = 980 ; B = 300; C = 100

  2. BOption (b)

    A = 880 ; B = 200 ; C = 300

  3. COption (c)

    A = 900 ; B = 300 ; C = 180

  4. DOption (d)

    A = 800 ; B = 300 ; C = 280

View answer & explanation

Correct answer

Answer: (c)C.

A = 900 ; B = 300 ; C = 180

Why this answer is correct

Shortcut Trick

Ratio of A : B : C is derived by making A common: A is 3 × 5 = 15 units.

Then B = 15 ÷ 3 = 5 units and C = 15 ÷ 5 = 3 units.

Total units = 15 + 5 + 3 = 23 units → 1,380.

1 unit = 1,380 ÷ 23 = 60.

A = 15 × 60 = 900; B = 5 × 60 = 300; C = 3 × 60 = 180.

∴ The correct answer is A = 900 ; B = 300 ; C = 180.

Alternate Method

Given: Total sum = 1,380. A = 5C and A = 3B.

Formula: Ratio = A : B : C

⇒ A : B = 3 : 1 and A : C = 5 : 1

⇒ To equalize A, multiply (A : B) by 5 and (A : C) by 3.

⇒ A : B : C = 15 : 5 : 3

⇒ Sum of ratios = 15 + 5 + 3 = 23

⇒ Share of A = (15 ÷ 23) × 1,380 = 15 × 60 = 900

⇒ Share of B = (5 ÷ 23) × 1,380 = 5 × 60 = 300

⇒ Share of C = (3 ÷ 23) × 1,380 = 3 × 60 = 180

∴ The correct answer is A = 900 ; B = 300 ; C = 180.

Additional Information

Ratio Balancing

When one variable is related to two others, find the LCM of its coefficients to normalize the entire ratio chain.

Division of Proportions

Individual Share = (Individual Ratio ÷ Sum of all Ratios) × Total Value.

Inverse Ratio

If mA = nB = pC, then the ratio A : B : C is (1/m) : (1/n) : (1/p).

Question 96

Which Indian city was included in the UNESCO Creative Cities Network in 2017 for its rich musical tradition?

  1. AOption (a)

    Begaluru

  2. BOption (b)

    Chennai

  3. COption (c)

    New Delhi

  4. DOption (d)

    Lucknow

View answer & explanation

Correct answer

Answer: (b)B.

Chennai

Why this answer is correct

The correct answer is option 2 i.e Chennai.

  • Chennai was included in the UNESCO Creative Cities Network in 2017 for its rich musical tradition.
  • After Jaipur and Varanasi, Chennai became the third Indian city on the UNESCO Creative Cities list.
  • UNESCO Creative Cities Network List highlights its members’ creativity within seven fields:  Crafts and Folk Art, Design, Film, Gastronomy, Literature, Media Arts, and Music.
  • Right now the list includes a total of 180 cities in 72 countries.
Bengaluru- The city is known as the silicon valley of India. - India's first helicopter-taxi service launched in Bengaluru.
New Delhi- Capital of India. - The city was designed by British architects Sir Edwin Lutyens and Sir Herbert Baker.
Lucknow- Capital of the state of Uttar Pradesh. - Historically, Lucknow was the capital of the Awadh region, controlled by the Delhi Sultanate.

Question 97

The following pie chart shows the information on sales of a toy-making company "XYZ" for 2017-18 financial year 

The total revenue made by sales of the toys is Rs. 38,72,00/- which type of toys made the least revenue for the company?

  1. AOption (a)

    Musical toys

  2. BOption (b)

    Activity toys

  3. COption (c)

    Learning blocks

  4. DOption (d)

    Soft toys

View answer & explanation

Correct answer

Answer: (b)B.

Activity toys

Why this answer is correct

Given:

Total revenue made by sale of toys = Rs.3, 87,200

Activity percentage = 5%

Calculation:

Activity toys is least among all other toys.

Revenue generated by activities toys = 5% of 387200

⇒ (5/100) × 387200

⇒ Rs.19360

Question 98

Which of the following has the highest value?

  1. AOption (a)

    10 power 11

  2. BOption (b)

    12 power 9

  3. COption (c)

    5 power 5

  4. DOption (d)

    11 power 10

View answer & explanation

Correct answer

Answer: (a)A.

10 power 11

Why this answer is correct

Concept:

Try to make base as close possible then compare their values

Calculation:

1011 and 1110

Divide by 1010

⇒ 10 and (1.1)10, clearly, 10 > (1.1)10

⇒ 1011 > 1110

Now, 1011 and 129

Divide by 109

⇒ 100 and (1.2)9, clearly, 100 > (1.2)9

⇒ 1011 > 129

Now, 1011 and 55

Clearly, 1011 > 55

∴ 1011 has the highest value.

Alternate Method Concept used:-

⇒ log ax = xlog a

Calculation:-

Taking log for all numbers-

⇒ 1011 = 11log10 = 11 × 1 = 11     ∵ log10 = 1

⇒ 129 = 9log12 = 9 × 1.07 = 9.63    ∵ log12 = 1.07

⇒ 55 = 5log5 = 5 × 0.69 = 3.45        ∵ log5 = 0.69

⇒ 1110 = 10log11 = 10 × 1.04 = 10.4     ∵ log11 = 1.04

∴ 1011 has the highest value.

Question 99

5% population of a town died of some epidemic and 8% of the remaining population left in panic. If the population of the town now is 88,274, find the population of the town at the beginning.

  1. AOption (a)

    99, 800

  2. BOption (b)

    1,21,600

  3. COption (c)

    1,01,000

  4. DOption (d)

    84, 500

View answer & explanation

Correct answer

Answer: (c)C.

1,01,000

Why this answer is correct

Shortcut Trick

Let the initial population be P.

Remaining after 5% death = 95/100 of P

Remaining after 8% left = 92/100 of (95/100 of P)

P × 0.95 × 0.92 = 88,274

P = 88,274 ÷ (0.95 × 0.92) = 1,01,000

∴ The correct answer is 1,01,000.

Alternate Method

Given:

⇒ Final population = 88,274

⇒ Death rate = 5%

⇒ Leaving rate = 8%

Calculations:

⇒ Let Initial Population = x

⇒ Population after 5% died = x − (5% of x) = 0.95x

⇒ Population after 8% of remaining left = 0.95x − (8% of 0.95x)

⇒ Final Population = 0.95x × (1 − 0.08) = 0.95x × 0.92

⇒ 0.874x = 88,274

⇒ x = 88,274 ÷ 0.874

⇒ x = 1,01,000

∴ The correct answer is 1,01,000.

Additional Information

Successive Percentage Change

When a value is changed by a% and then by b%, the effective change is [a + b + (a × b)/100]%.

Population Depreciation Formula

Final Population = Initial Population × (1 − R1/100) × (1 − R2/100), where Rn are the reduction rates.

Multiplier Method

A 5% decrease corresponds to a multiplier of 0.95, and an 8% decrease corresponds to a multiplier of 0.92.

Question 100

Who won the 2017 Discovery Education 3M Young Scientist Challenge for inventing a quick, low-cost test to detect lead-contaminated water?

  1. AOption (a)

    Loushik Chakraborty

  2. BOption (b)

    Divya Sharma

  3. COption (c)

    Gitanjali Rao

  4. DOption (d)

    Shiv Prakash Singh

View answer & explanation

Correct answer

Answer: (c)C.

Gitanjali Rao

Why this answer is correct

The correct answer is option 3 i.e Gitanjali Rao.

  • Gitanjali Rao won the 2017 Discovery Education 3M Young Scientist Challenge for inventing a quick, low-cost test to detect lead-contaminated water.
  • Gitanjali Rao is an American inventor.
  • In 2018 she was awarded the United States Environmental Protection Agency President’s Environmental Youth Award.
  • In 2019 she was awarded the Top Health Pillar Prize for the TCS Ignite Innovation Student Challenge.

100 questions in the full paper