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The correct answer is A - iii, B - iv, C - i, D - ii.

Key-points

• Based on the descriptions given, the epithelial tissues can be matched to their corresponding locations in the body as follows:
• Pseudostratified Columnar Epithelium  - Respiratory Tract
• Stratified Squamous Epithelium - Skin
• Simple Squamous Epithelium - Lining of Blood Vessels
• Simple Cuboidal Epithelium - Ducts of Salivary Glands

Additional Information

• Pseudostratified Columnar Epithelium (Respiratory Tract):
• This is a single-layered tissue with nuclei at different levels, making it appear stratified.
• It lines the trachea and bronchi, where it secretes and moves mucus using its cilia.
• Stratified Squamous Epithelium (Skin):
• This multi-layered tissue is found in areas exposed to friction like the skin.
• The cells on the surface are flat, while those underneath can be cuboidal or columnar.
• This tissue protects underlying tissues from injury, infection, and dehydration.
• Simple Squamous Epithelium (Lining of Blood Vessels):
• This is a single layer of flat cells that allows rapid diffusion or transport of substances.
• Found in the lining of blood vessels, it reduces friction for the flowing blood.
• Simple Cuboidal Epithelium (Ducts of Salivary Glands):
• Consisting of a single layer of cube-shaped cells, this tissue is involved in secretion, absorption, and excretion.
• Found in glands and their ducts like salivary glands, it helps in transporting saliva to the mouth.

Given : 

\(\frac{5^3 \times 27 \times 10^3}{5^6 \times 3^2 \times 4}\)

Concept Used 

Indices law

Calculation :

\(\frac{5^3 \times 27 \times 10^3}{5^6 \times 3^2 \times 4}\)

⇒\(\frac{5^3 \times 3^3 \times (5\times2)^3}{5^6 \times 3^2 \times 2 ^2}\)

⇒\(\frac{5^{(3-6) }\times 3^{(3-20)} \times 5^3 \times 2 ^3}{ 2 ^2}\)

⇒\({5^{(-3) }\times 3^{(1)} \times 5^3 \times 2 ^{(3-2)}}\)

⇒\({5^{(-3 +3) }\times 3^{(1)}\times 2 ^{1}}\)

⇒6 

The required value of \(\frac{5^3 \times 27 \times 10^3}{5^6 \times 3^2 \times 4}\) is 6.

Shortcut Trick

Subtract the coefficients of the variable: 7 − 5 = 2 units.

Add the constants (since one is reduced and one is added): 14 + 6 = 20.

Equate the differences: 2 units = 20.

Therefore, 1 unit = 20 ÷ 2 = 10.

∴ The correct answer is 10.

Alternate Method

Given:

Let the unknown number be x.

Seven times the number = 7x

Reduced by 14 = 7x − 14

Sum of five times the number and 6 = 5x + 6

Calculations:

⇒ 7x − 14 = 5x + 6

⇒ 7x − 5x = 6 + 14

⇒ 2x = 20

⇒ x = 20 ÷ 2

⇒ x = 10

∴ The correct answer is 10.

Additional Information

Linear Equations in One Variable

An equation of the form ax + b = cx + d where x is the variable and its highest power is 1.

Transposition Rule

When a term is moved from one side of the equation to the other, its sign changes (+ becomes −, and − becomes +).

Verification of Roots

Substitute the value back into both sides: LHS = 7(10) − 14 = 56 | RHS = 5(10) + 6 = 56. Since LHS = RHS, the solution is correct.

Given: 

28 March 2017 was a Tuesday.

Concept used:

Divide the number of days into seven to determine the odd days. After division, we are left with the remainder which are specified as odd days for the particular number.

2017 is not a leap year so days in February will be 28 days.

Consider, 

Monday= 1, Tuesday = 2, Wednesday = 3, Thursday = 4, Friday = 5, Saturday = 6, Sunday = 7 or 0

Calculation:

Number of odd days after 12 February 2017 to 28 February 2017 = 28 - 12 = 16 = 2 odd days

Number of odd days from 1^st march till 28^th march, 2017 = 28 = 0 odd days

Total number of odd days from 12 February 2017 till 28^th March 2017 = 2 + 0 = 2

odd days = 2 odd days

So, the day on 12 February 2017 = Tuesday - 2 = 0 means Sunday.

Hence, 'Sunday' is the correct answer.

Given : 

W # 2 ∞ D @ 4 Y 3 D Ω R 7 & S F @ 6 ^ < X 2 2

The logic follows here is as,

• Letter \(\Large \rightarrow\) Symbol \(\large\rightarrow\) Number

here, there are 3 symbols each of which is immediately preceded by a letter and immediately followed by a number.

Hence, 'option 3' is the correct answer.

Shortcut Trick

For a rate of 10% and time of 2 years, the effective Compound Interest rate is 10 + 10 + (10 × 10)/100 = 21%.

Total Amount percentage = 100% + 21% = 121%.

Total amount paid = 121% of ₹9,000

⇒ 1.21 × 9000 = ₹10,890.

∴ The correct answer is ₹10,890.

Alternate Method

Given:

Principal (P) = ₹9,000

Rate of Interest (R) = 10% per annum

Time (n) = 2 years

Formula Used:

Amount (A) = P(1 + R/100)ⁿ

Calculations:

⇒ A = 9000 × (1 + 10/100)²

⇒ A = 9000 × (110/100) × (110/100)

⇒ A = 9000 × (11/10) × (11/10)

⇒ A = 9000 × 121 / 100

⇒ A = 90 × 121

⇒ A = 10890

∴ The correct answer is ₹10,890.

Additional Information

Compound Interest (CI)

CI = Amount − Principal. It is the interest calculated on the initial principal and also on the accumulated interest of previous periods.

SI and CI Difference for 2 Years

The difference between Simple Interest and Compound Interest for 2 years is given by: D = P × (R/100)².

Half-Yearly Compounding

When interest is compounded half-yearly, the rate is halved (R/2) and the time is doubled (2n) in the formula A = P(1 + R/200)²ⁿ.

The correct answer is '17°C to 24°C'.

Key Points

• Climatic conditions: 
• Mean annual rainfall is 75 cm to 125 cm.
• The average annual temperature is 17°-24°C.
• Humidity is 80 per cent.
• Distribution:
• Eastern Himalayas to the east of 88°E longitude at altitudes varying from 1000 to 2000 m.

Additional Information

• Characteristics Forests of evergreen species.
• Commonly found species are evergreen oaks, chestnuts, ash, beech, sales and pines.
• Climbers and epiphytes [a plant that grows non-parasitically on a tree or other plant] are common.
• These forests are not so distinct in the southern parts of the country.
• They occur only in the Nilgiri and Palni hills at 1070-1525 metres above sea level.
• It is a “stunted rainforest” and is not so luxuriant as the true tropical evergreen.
• The higher parts of the Western Ghats such as Mahabaleshwar, the summits of the Satpura and the Maikal Range, the highlands of Bastar and Mt. Abu in the Aravali Range carry sub-types of these

The correct answer is NaCl + H2O + CO2 + NH3  → NH4Cl + NaHCO3.

Key-points

• The Chemical Reaction:
• NaCl + H2O + CO2 + NH3 → NH4Cl + NaHCO3
• In this reaction, the ammonia (NH3) combines with the water (H2O) and the carbon dioxide (CO2) to form ammonium bicarbonate (NH4HCO3).
• This ammonium bicarbonate then reacts with the sodium chloride (NaCl) in a double displacement reaction, forming ammonium chloride (NH4Cl) and sodium bicarbonate (NaHCO3).
• This reaction occurs in a solution and can be influenced by conditions such as temperature, pressure, and pH. Under certain conditions, this reaction could be used to capture and neutralize CO2, a greenhouse gas, potentially contributing to climate change mitigation strategies.

​Additional information

• Reactants:
• Sodium chloride (NaCl) - Sodium chloride is a salt composed of sodium ions (Na+) and chloride ions (Cl-). It's a common compound, which, among many other uses, is well-known as table salt.
• Water (H2O) - Water is a simple inorganic compound that is a crucial life-sustaining molecule. It's a solvent for many ionic compounds like salts.
• Carbon dioxide (CO2) - Carbon dioxide is a linear molecule with a central carbon atom double bonded to two oxygen atoms. It's a waste product in organisms during respiration, but it's also used in various industrial processes.
• Ammonia (NH3) - Ammonia is a compound of nitrogen and hydrogen. It's a colorless gas with a pungent smell. It's used in several industries, including agriculture (as a fertilizer), pharmaceuticals, and cleaning supplies.
• ​Products:
• Ammonium chloride (NH4Cl) - Ammonium chloride is a product of ammonia (NH3) and hydrochloric acid (HCl). It's used in various applications such as a nutrient in yeast fermentation and as an ingredient in cough medicine.
• Sodium bicarbonate (NaHCO3) - Sodium bicarbonate, also known as baking soda, is a white crystalline powder. It's used in baking as a leavening agent, in medicine to soothe heartburn and acid indigestion, and in cleaning products.

The correct answer is We should not place waste in plastic bags and discard them. 

Key Points

• The major impact of plastic bags on the environment is that it takes many years for them to decompose.
• In addition, toxic substances are released into the soil when plastic bags perish under sunlight and, if plastic bags are burned, they release a toxic substance into the air causing ambient air pollution.
• Waste from plastic bags poses a serious environmental danger to human and animal health. Thus, we should not place waste in plastic bags and discard them.
• If plastic bags are not properly disposed of, they can impact the environment by causing littering and stormwater drain blockages.
• Animals may also get tangled and drown in plastic bags.
• Animals often confuse the bags for food and consume them, therefore blocking their digestive processes.

Hence statement 2 is correct. 

• Plastic bags when used to keep food release toxic chemicals into them, which directly harm us and our digestive system.
• Burning of plastic bags releases a lot of greenhouse gases which harms the environment as well as our health.
• By law, shopkeepers are restricted from using plastic bags, instead, they are bags by law.

Hence the statement 1, 3, and 4 are incorrect.

The correct answer is '-3D' .

Key-points:

• Converging lens has positive focal length f₁ = 50 cm
• Diverging lens has negative focal length f₂ = -20 cm
• The focus of the combination of two lenses is given by

\({1\over f}={1\over f_1}+{1\over f_2}\)

\({1\over f}={1\over 50}+{1\over-20}\)

\({f}={100\over-3}\)

• The power of any lens is given by \(P={100\over f}\)
• P = -3 D