AFCAT 28 Aug 2021 (Shift 1) Memory Based Paper (Previous Year Paper)

The correct answer is graphite.

• Black lead is also known as Graphite.

Key Points

• Graphite
• It is a pure form of Carbon.
• This Allotrope of Carbon is composed of Flat Two-dimensional layers of Carbon Atoms which are arranged in a Hexagonally form.
• It is black, slippery, and soft solid. This property of Graphite is considered because it cleaves easily between the Layers.
• It is also called the Black lead.

Additional Information

• Graphene:
• It is also an allotrope of carbon
• It is a sheet of a single layer of carbon atoms
• Layers of graphene make up graphite.
• The strong covalent bonds between the carbon atoms of graphene.
• Graphite is soft because it has weak intermolecular forces between its layers.
• It is widely used in electronics.
• Diamond:
• It is a well-known allotrope of carbon.
• It exhibits high hardness, high melting point, thermal conductivity, and high dispersion of light.
• It is the hardest known natural mineral.
• It is widely used in cutting, jewellery, and as a potential semiconductor material.

The correct answer is 1950.

Key Points

• The Constitution of India had a firm inclusion of the need for ‘Economic and Social Planning. After independence, the stage was set for the formal launching of planning in the country.
• For economic planning for the whole economy at the national level, the requirement of a permanent expert body was felt.
• Thus, in March 1950 the  Planning Commission (PC) was set up.
• The PC was set up by a Cabinet Resolution.
• Few important points about the Planning Commission are:  
• It was an extra-constitutional (i.e., non-constitutional) body which was a non-statutory body too.
• It was a type of an advisory body to the Government of India.
• PC was a  ‘think tank’ for economic development.
• Its ex-officio chairman was the Prime Minister, it also had a provision of a Deputy Chairman.
• The function of the DC was to co-ordinate the work of the commission.
• It had no cap on the number of members, as many area experts are required by the particular proposed period of planning.
• Autonomous body entitled to form their own views on important issues and place them before the governments. PC worked closely with both the central and state governments.
• The ‘demand for grants’ for PC was included in the budget demand for the Cabinet Secretariat.
• On January 1, 2015,  the important era in the economic history ended when the Planning commission was abolished by the government and in place of it a newly created body—the NITI Aayog was established.

The correct answer is option 3 i.e. the Brahmaputra

• 'Majuli' is the largest river island in the world.
• Majuli island is a large river island located in the middle of the 'Brahmaputra River' in Assam.
• This island was formed due to a change in direction of the 'Brahmaputra River' and its tributaries.
• The Brahmaputra river origin from the Manasarovar Lake in Tibet and flow through Tibet, India, and Bangladesh.
• The Godavari is the longest river of South India it is known as "Dakshin Ganga".
• The Kaveri river origin on the Brahmagiri range in the Western Ghats, of Kodagu district of the state of Karnataka.

The correct answer is South Korea.

• South Korea is the land of Morning Calm.

Key Points

• South Korea is called ‘Morning Calm’.
• The title is most suited because of its spellbinding natural beauty of picturesque high mountains and clear waters and its splendid tranquillity, particularly in the morning.
• Seoul is the capital of South Korea.
• The currency of South Korea is Won.
• Yoon Suk-yeol is the current (2022) president of South Korea.
• Han Duck-soo is the current prime minister (2022) of South Korea.

Additional Information

• Japan is called Nihon (Nippon), meaning, “the sun's origin".
• Finland is known as the Land of the Thousand Lakes.
• Thailand is called the Land of White Elephants.

The correct answer is Rafale.

• Scalp missile is integrated with Rafale aircraft.

Key Points

• Rafale Aircraft: 
• The Dassault Rafale is a French twin-engine, canard delta wing, multirole fighter aircraft designed and built by Dassault Aviation.
• The first five Indian Air Force (IAF) Rafale aircraft have arrived at Air Force Station, Ambala on Wednesday, 29 July 2020.
• The Indian Air Force has inducted 11 of the 36 Rafale jets ordered by New Delhi at a cost of Rs 59,000 crore.
• Rafale jets manufactured by French aerospace major Dassault Aviation, are India’s first major acquisition of fighter planes in 23 years.
• It carries a range of potent weapons such as MBDA’s (France-based Weapons Manufacturing Company) Meteor Beyond visual range air-to-air missile, Scalp Cruise Missile.

The correct answer is chess.

Key Points

The correct answer is Wilson Jones.

Key Points

• Wilson Lionel Garton Jones, was a professional player of billiards from India.
• He made three initial unsuccessful attempts at the world title - starting with 1951 in London, followed by the world championships in Calcutta (1952) and Sydney (1954).
• In 1958, the world championship returned to Calcutta, where Jones hit his stride.
• In Calcutta's Great Eastern Hotel, Jones pulled off the biggest upset in the world game at the time and became the first Asian to win it.
• Wilson was the first Indian to be a World Champion in any sport.

Additional Information

• The Government of India awarded him the Arjuna Award in 1963, the Padma Shri in 1965, and the Dronacharya Award in 1996.
• Wilson died of a heart attack in 2003.
• Pankaj Advani, Michael Ferreira, and Geet Sethi are all professional players of billiards from India.

The correct answer is ​Shah Jahan.

Key Points

• The Red Fort and Jama Masjid are two of the many architectural gems built in Shah Jahan's reign.
• Even though Shah Jahan is famously known for the Taj Mahal,  the Red Fort and Jama Masjid are the other wonders he built in Delhi itself.
• The Red Fort was built in 1639 as his palace for his then capital back then known as Shahjahanad.
• The Jama Masjid was finished in 1656 with a name of Masjid-e-Jahan Numa.

Uruguay was the first host country of the FIFA (Federation Internationale de Football Association) World Cup.

Key Points

• The FIFA World Cup was first organized in 1930, when FIFA, the governing body for football in the world, agreed to stage an international men's football competition under FIFA president Jules Rimet's reign, who put this idea into effect.
• The inaugural competition, which took place in 1930, was challenged as a final tournament with just 13 teams invited by the organisation.
• The first official international football match between Scotland and England was played at Glasgow in 1872.
• Uruguay also became the first champion of the FIFA World Cup.
• France got the FIFA World Cup title 2nd times in 2018.

The correct answer is Bhutan.

Key Points

• Archery is the national game of Bhutan.
• Bhutan became a member of the United Nations in 1971.
• The same year Bhutan declared archery as its national game.
• Archery is played during religious and secular public holidays in Bhutan.
• The peoples of Bhutan take part in archery competition inside as well as outside the country.
• Bhutanese archery team even participated in the Olympics.

Additional Information

• Important Facts about Bhutan
• ​The current king of Bhutan is Jigme Khesar Namgyel Wangchuck.
• The official language of Bhutan is Dzongkha.
• The capital of Bhutan is Thimpu.
• The currency of Bhutan is Ngultrum.
• The parliament of Bhutan is known as Tshogdu.
• The founder of Bhutan is Zhabdrung Ngawang Namgyel.
• Gangkhar Puensum is the highest point in Bhutan—and the highest unclimbed mountain in the world.
• The word “Bhutan” translates to “Land of the Thunder Dragon.” It earned the nickname because of the fierce storms that often roll in from the Himalayas.
• The most important Bhutanese festival is Tshechu.
• Ema Datshi is the National dish(Food) of Bhutan.
  
• There are three important rivers of Bhutan:

1. Drangme Chhu: It is the largest river in Bhutan. In India, it is known as the Manas river. It originates in the West Kameng District of Arunachal Pradesh in India.
2. Wang Chhu: It originates from the Himalayan glaciers in Tibet.
3. Torsa Chhu: It originates from the Chumbi Valley in Tibet. It is the smallest river system in Bhutan.

 

The correct answer is Bakelite.

Key Points

• Bakelite is the world's first man-made polymer.
• Bakelite is a polymer made up of the monomers phenol and formaldehyde.
• This phenol-formaldehyde resin is a thermosetting polymer.
• Bakelite is the commercial name for the polymer obtained by the polymerization of phenol and formaldehyde.
• These are one of the oldest polymers that were synthesized by man.
• Phenol is made to react with formaldehyde.
• The condensation reaction of the two reactants in a controlled acidic or basic medium results in the formation of ortho and para hydroxymethyl phenols and their derivatives.

Additional Information

• Polymer   
• A substance made from long chains of repeating groups of atoms.
• Manufactured polymers include nylon, polyvinyl chloride (better known as PVC), and many types of plastics.
• Natural polymers include rubber, silk, and cellulose (found in plants and used to make paper, for example).
• Polyvinyl chloride (PVC)   
• Plastic is formed by using heat to turn a liquid resin into a solid.
• The plastic can be soft and flexible or rigid and hard.
• The raw ingredients consist primarily of chlorine and carbon.
• Nylon is made from two monomers, each containing six carbon atoms, so the product is known as Nylon 6,6.
• On reaction, an OH group is lost from the acid molecule and one hydrogen from the amine molecule, so a molecule of water is eliminated, and an amide link is formed between the two monomers.

The correct answer is Bairam Khan.

Key Points

• Muhammad Bairam Khan was an important military commander, and later commander-in-chief of the Mughal army.
• He was a powerful statesman and regent at the court of the Mughal Emperors, Humayun and Akbar.
• He was also the guardian, chief mentor, adviser, teacher and the most trusted ally of Akbar.

Additional Information

Navratanas of Akbar's court

The correct answer is Uttar Pradesh.

Key Points

• Thumri is a folk dance of Uttar Pradesh.
• The term "thumri" is derived from the Hindi verb thumakna.

Additional Information

​Folk dances:

The correct answer is Hindustan Copper Limited.

• Hindustan Copper Limited (HCL) is a Schedule 'A' Miniratna Category - I Central Public Sector Enterprise under the administrative control of the Ministry of Mines, Government of India.
• It was incorporated on 9th November 1967.

Key Points

• Eligibility Criteria of the Maharatna Status:
• Three years with an average annual net profit of over Rs. 2500 crore, or
• Average annual Turnover of Rs. 20,000 crore for 3 years, or
• Average annual Net worth of Rs. 10,000 crore for 3 years, or
• Benefits for Investment: 
• Rs. 1,000 crore – Rs. 5,000 crore, or free to decide on investments up to 15% of their net worth in a project.

Important Points

• Maharatna CPSEs (As of January 2020)
• Bharat Heavy Electricals Limited
• Bharat Petroleum Corporation Limited
• Coal India Limited
• GAIL (India) Limited
• Hindustan Petroleum Corporation Limited
• Indian Oil Corporation Limited
• NTPC Limited
• Oil & Natural Gas Corporation Limited
• Power Grid Corporation of India Limited
• Steel Authority of India Limited

The correct answer is Neptune.

• Neptune is the eighth and the farthest known planet from the sun in the solar system.
• Neptune is the 'God of the sea' based on Roman mythology.
• Neptune has 14 known moons.
• Hippocamp is the moon of Neptune
• Hippocamp was discovered on 1 July 2013.
• It was discovered by astronomer Mark Showalter.
• Neptune is the planet that takes maximum time for revolution..
• Neptune has the longest year.
• The great dark spot can be seen in Neptune.

Additional Information

The correct answer is Abu Dhabi.

Key Points

• International Renewable Energy Agency (IRENA):
• It is the first international organization to focus exclusively on renewable energy, addressing needs in both industrialized and developing countries.
• It was founded in 2009 and its statute entered into force on 8 July 2010.
• It is headquartered in Masdar City, Abu Dhabi.

Additional Information

• IRENA is an official United Nations observer.
• IRENA aims to become the main driving force in promoting a transition towards the use of renewable energy on a global scale:
• Acting as the global voice for renewable energies, IRENA provides advice and support to governments on renewable energy policy, capacity building, and technology transfer.
• IRENA will also co-ordinate with existing renewable energy organizations, such as REN15.

Important Points

• India has become the 77th founding member of IRENA.

The correct answer is ​John Lewis.

Key Points

• John Robert Lewis was an American politician and civil rights activist who served in the United States House of Representatives for Georgia's 5th congressional district from 1987 until his death in 2020.
• He was the chairman of the Student Nonviolent Coordinating Committee from 1963 to 1966.
• In his speech at the March on Washington on 28 Aug 1963 he said the following important points:
• We march today for jobs and freedom, but we have nothing to be proud of.
• “One man, one vote” is the African cry. and it is ours too.
• We do not want our freedom gradually, but we want to be free now!

The correct answer is Ghadar Party.

Key Points​

• Ghadar Party
• It was an international political party consisting of expatriate Indians to overthrow British rule in India.
• The Ghadar Party initially named the Pacific Coast Hindustan Association was formed on 15 July 1913 in San Franciso of the United States under the leadership of Lala Har Dayal, with Sohan Singh Bhakna as its president.
• The Ghadar party found a large support base among Indian expatriates living in the United States, Canada, East Africa, and Asia.
• The Ghadar Movement began to lose steam following the heavy-handed British crackdown.
• During the conclusive years of World War I, in 1917 the Ghadar Party fractured into a Communist and a Socialist faction.

Additional Information

• The Indian Association:
• It was the first avowed nationalist organization founded in British India by Surendranath Banerjee and Ananda Mohan Bose in 1876
• Bengal-British India Society:
• It was founded in Calcutta in 1843.
• India League**:**
• The India League originally was a Britain-based organisation whose aim was to campaign for the full independence and self-governance of India.
• It was formally established in 1928 by Krishna Menon.

The correct answer is option 3, i.e. Atharva Veda.

• The Atharva Veda is one of the four Vedas which mentions about magical rituals and charms.
• The Atharva Veda is sometimes called the "Veda of magical formulas”, an epithet declared to be incorrect by other scholars.
• The Samhita layer of the text represents a developing 2^nd millennium BCE tradition of magico-religious rites to address superstitious anxiety, spells to remove maladies believed to be caused by demons, and herbs- and nature-derived potions as medicine.
• Vedas are the collection of Hindu and other ancient religious texts written in ancient India between 1500-1000 BCE.
• Rigveda is the oldest Veda of all.

The correct answer is North atlantic.

• Greenland is located between the Arctic Ocean and the North Atlantic Ocean.

Key Points

• It is the world’s biggest island by area and the total area of Greenland is 2.16 million square kilometers.
• Greenland possesses the world's second-largest ice sheet.
• Almost 80 percent of the landmass of Greenland is covered by an ice cap.
• The climate of Greenland is arctic to subarctic, with cool summers and cold winters.
• The vegetation is generally sparse, with a patch of forested lands.
• With an estimated population of 56,480, it is one of the least densely populated countries in the world.

The correct answer is Andre Agassi.

Key Points

• "The Las Vegas Kid**" and "Punisher"** is the nickname of Andre Agassi who is an American retired professional tennis player.
• The "Indian Jack" is the nickname of Jack Jacobs was an American and Canadian football player in the National Football League and Western Interprovincial Football Union.
• "Buddha" is the nickname of James Franklin Edwards is an American retired professional basketball player. He was nicknamed "Buddha" for his appearance.
• "The Wall" is the nickname of former Indian cricketer and captain of the Indian national team Rahul Dravid who has been honoured with the Padma Shri and the Padma Bhushan award.

The correct answer is Jhelum.

Key Points

• Wular Lake is the largest freshwater lake in India.
• It lies in the Kashmir Valley.
• It is located in the Bandipora district in Jammu and Kashmir.
• It is also known as "Mahapadma Saras".
• It is the second-largest freshwater lake in Asia.
• Jhelum River is the main source of water for Wular Lake. Hence option 3 is correct.
• It is formed as a result of tectonic activity.
• It also has a small island in its centre called the ‘Zaina Lank’.
• It was designated as a Ramsar site on 23rd March 1990.

Additional Information

• Jhelum River:
• ​The Jhelum River is a tributary of Indus and is located in eastern Pakistan, northern India.
• It originates from the Verinag Spring in Anantnag district of Jammu and Kashmir and flows into the Chenab river.
• Right Bank Tributaries of Jhelum - Pohru, Sandrin, Arapal, Sindh, Arapath, Bringi, and Liddar. Left Bank Tributaries- Ningal, Vishav, Romshi, Doodganga, Rambiara, and Sukhnag.

The correct answer is South Africa.

Key Points

• The Kalahari Desert
• It is a large semi-arid sandy savanna in Southern Africa extending for 900,000 square kilometers, covering much of Botswana, parts of Namibia, and regions of South Africa. Hence, Option 1 is correct.
• The Sahara is a desert located on the African continent.
• It is the largest hot desert in the world and the third-largest desert overall after Antarctica and the Arctic region.
• The Atacama Desert is a desert plateau in South America covering a 1,000-km (600-mi) strip of land on the Pacific coast, west of the Andes mountains.
• The Kalahari Desert is part of one giant sand basin that stretches from the Orange River in Angola to Namibia in the west, Zimbabwe in the east, and South Africa.
• The landscape in this largely unexplored territory provides a marked contrast from the south and east of the country.
• Black-maned Kalahari lions are a highlight of the desert; found in the Kgalagadi Transfrontier Park in the southwestern corner of the country, they may be resting in the dry river beds or under the shade of the sparse trees.
• The environment here for the lions is more competitive than more luscious parts of Southern Africa, with fewer herbivores on offer to predators due to the restricted rainfall, meaning that only the strongest of these huge black-maned beasts prevail.

Additional Information

• The Atacama Desert
• It is a desert plateau in South America covering a 1,600 km strip of land on the Pacific coast, west of the Andes Mountains.
• The Atacama Desert is a cool, arid region in northern Chile, 600 to 700 miles (1,000 to 1,100 km) long from north to south.
• Its limits are not exactly determined, but it lies mainly between the south bend of the Loa River and the mountains separating the Salado-Copiapó drainage basins.
• To the north, the desert continues to the border of Peru.
• The Thar Desert
• It is also known as the Great Indian Desert, is a large, arid region in the northwestern part of the Indian subcontinent that covers an area of 200,000 km² (77,000 sq mi) and forms a natural boundary between India and Pakistan.
• It is the world's 17th-largest desert and the world's 9th-largest hot subtropical desert.
• About 85% of the Thar Desert is located within India, and the remaining 15% is in Pakistan.
• The Thar Desert forms about 4.56% of the total geographic area of India.
• More than 60% of the desert lies in the Indian state of Rajasthan, and it extends into Gujarat, Punjab, and Haryana, and the Pakistani province of Sindh.
• Within Pakistan's Punjab province, the Thar continues as the Cholistan Desert.
• The desert comprises a very dry part, the Marusthali region in the west, and a semidesert region in the east with fewer dunes and slightly more precipitation.
• The Arabian Desert
• It is a vast desert wilderness in Western Asia.
• It stretches from Yemen to the Persian Gulf and Oman to Jordan and Iraq.
• It occupies most of the Arabian Peninsula, with an area of 2,330,000 square kilometers (900,000 sq mi).
• It is the fifth-largest desert in the world and the largest in Asia. At its center is Ar-Rub al-Khali (The Empty Quarter), one of the largest continuous bodies of sand in the world.

Image of all the deserts in the world:

The correct answer is Vitamin D.

Key Points 

• Rickets is a deficiency disease of Vitamin D.
• Vitamin D helps to increase the rate of absorption of calcium into the body.
• Vitamin D is required for the proper development of bones and cartilage.
• Vitamin D is also called the sunshine vitamin.

Additional Information 

• Vitamin A is also called Retinol(Chemical name).
• It helps in good eyesight and maintains healthy eyes.
• Night blindness and Xerophthalmia are the deficiency diseases of Vitamin A.
• Hemorrhage is a deficiency disease caused due to lack of Vitamin K.
• Vitamin E is a fat-soluble vitamin.
• Sterility is the deficiency disease of Vitamin E.

Arranging the given letter-clusters in their natural sequence we get the following words:

1. APRUIJ → JAIPUR
2. LINAMA → MANALI
3. GLEUMBA → BELGAUM
4. OSORIN → ORISON

Jaipur, Manali, and Belgaum are the names of locations in India whereas orison means a prayer.

Hence, "OSORIN" is the odd one among the given options.

1. Nephrology concerns the study of the kidneys.
2. Similarly, Hematology is the study of blood and blood disorders.

Hence, Hematology is related to blood in the same way as Nephrology is related to kidneys.

Additional Information

The option figure in which the given figure is embedded is option ‘1’.

Hence, the correct answer is "option (1)".

The least possible Venn diagram that best represents the relationship among the classes Cobra, Moth, Salamander is as follows:

1. Cobra is the common name of a group of snakes.
2. Moths are a group of insects.
3. Salamanders are a group of amphibians.

 

Thus, there is no common relation between any of these groups.

 

Hence, the correct answer is "Option 2".

Logic followed here is:

Here, all the capital city with respect of country wrongly given except, VIEENA - AUSTRIA. Vieena is the capital city of Austria.

Additional Information

 

Hence, the correct answer is **"**VIEENA - AUSTRIA".

1. Some goods are transported by ships.
2. Some goods are transported by trucks.
3. Also, there are some goods that are transported by other vehicles.

Thus, the Venn diagram that best represents the relationship among goods, ship, truck is as follows:

Hence, option 3 is the correct answer.

We have to check each option:

Figure A:

 

Here, figure has six sides and every alternate side have one inside line and one outside line

Figure B:

Here, figure has six sides and every alternate side have one inside line and one outside line.

Figure C:

Here, figure has six sides and every alternate side have one inside line and one outside line.

Figure D:

Here, the figure has six sides, But every alternate side do not  have one inside line and one outside.

Hence, the correct answer is "Option (4)".

The logic followed here is:

The sound of a Lion is called "Roar".

Similarly,

The sound of a Bear is called "Growl"

Additional Information

 

Hence, the correct answer is "Growl".

In the question figure, one of the dot lies in the region common to the circle, square, and rectangle only.

The second dot lies in the region common to the circle, triangle, and rectangle only.

The third dot lies in the region common to the square and rectangle only.

Only Figure (D) consist are these types of regions.

In Figure (A) (B) & (C) there is no region common to the circle, triangle and the rectangle only.

Hence, the correct answer is "Option 4".

In the question figure,

1. One dot is in the common area of one circle and one rectangle.
2. One dot is in the common area of one triangle and one circle and one square. 3. One dot is in the common area of one rectangle and one circle and one square. 

Here, in the given figures, Figure (d) is fulfill all required conditions.

Hence, the correct answer is "Option (3)".

In the question figure, one of the dot lies in the region common to all three figures.

The one dot lies in the region common to square and circle only.

The other dot lies in the region common to the circle only.

Only Figure (C) consist of these types of regions.

In the Figure (A), there is no common region for circle and square.

In the Figure (B) & (D) there is no common region for all the figures.

Hence, the correct answer is "Option 2".

In figure (X), the dot lies in the region common to circle, triangle and rectangle only.

In figures (B), (C) and (D), there is no common region to circle, triangle and rectangle only whereas in figure (A) there is the region where all three shapes lie together.

Hence, figure (A) is the correct answer.

In the question figure, one dot lies in the region common to the circle and triangle only.

One dot is lies in the region common to the circle and two quadrilateral only.

Other third dot lies in the region common to one of the quadrilateral, triangle and circle only.

Only figure (A) consist these types of region.

Figure (C) is not consist these dots, because they don't have a common region of quadrilateral, triangle and circle

Figure (B) is not consist these dots, because they don't have a common region of Circle and triangle only

Figure (D) is not consist these dots, because they don't have a common region of two quadrilateral and circle.

Hence, the correct answer is "Option A".

The logic followed here is :

• Carrots and parsnips are root vegetables.
• There are many other root vegetables like sweet potato, beetroot, onions etc.

Thus, the Venn diagram that best represents the relationship among root vegetables, carrot, parsnip is as follows:

Hence, option 4 is the correct answer.

The logic followed here is:

Except, 'Lord Tennyson' all other Governor-General belong to India.

 

Hence,the correct answer is  "Lord Tennyson".

The logic followed here is:

• England is an island in the Atlantic Ocean.

Similarly,

• Greenland is an island in the Arctic Ocean.

Hence, the correct answer is "Arctic ocean".

Additional Information Ocean: An ocean is "any of the large bodies of water into which the great ocean is divided". Separate names are used to identify five different areas of the ocean: Pacific (the largest), Atlantic, Indian, Southern (Antarctic), and Arctic (the smallest).

Island: An island is an isolated piece of habitat that is surrounded by a dramatically different habitat, such as water.

The logic followed here is:

Except "Turning points -  A. P. J. Abdul Kalam" all others books are written by some other author.

Additional Information

 

Hence, the correct answer is "Turning points - A. P. J. Abdul Kalam"

On observing all the options:

Option (1)

Here, 4 connected arrows are present.

Option (2)

Here, 4 connected arrows are present.

Option (3)

Here, 4 connected arrows are present.

Option (4)

Here, 5 connected arrows are present.

All Options Except option (4) are having 4 connected arrows but in option (4) there are 5 connected arrows so it is odd one out. as shown below:

Hence, the correct answer is "option (4)".

The logic followed here is:

1. Snakes and lizards are reptiles.
2. Some of the other reptiles are crocodiles, turtles etc.

Thus, the Venn diagram that best represents the relationship between Snake, Lizard and Reptiles is as follows:

Hence, option 4 is the correct answer.

The position of letter according to the English alphabet series:

The pattern followed here is:

Similarly,

Hence, "FNHTV" is the correct answer.

The pattern followed here is :

1. All the elements move in an anticlockwise direction in each step.

2. The first, third and fifth elements  according to anticlockwise direction are replaced by new elements in first step and After one gap this step is repeated.

3. Then the second, fourth and sixth elements  according to anticlockwise direction are replaced by new elements in the next step. After one gap this step is repeated.

Hence, the figure in option 4 is the correct answer.

The logic followed here is:

Each figure have 5 positions as shown in the figure above.

The element at position 1 moves to position 2. Here + is replace with G

The element at position 2 moves to position 3. Here G is replace with 

The element at position 3 moves to position 4. Here E replace with @

The element at position 4 moves to position 5. Here F is replace with $

The element at position 5 gets eliminated and a new figure appears at position 1.

Hence, the correct answer is "Option 3".

The pattern followed here is-

The shape or element in the upper right quadrant shifts to the lower left quadrant in the successive figure.

The shape or element in the lower right quadrant shifts to the upper right quadrant in the successive figure.

The shape or element in the upper left quadrant shifts to the lower right quadrant in the successive figure.

And a new shape or element is added to the upper left quadrant and the element or shape in lower left quadrant is removed in every successive step.

Here, Option 2 and 4 both can be correct answers but according to the last figure only option 4 is correct

.

Thus, figure 4 of the given options will replace the question mark.

Mistake Points Please observe the orientation of the star in both options. There is a slight difference in both options.

The logic followed here is:

1. In each step, the right-hand side element becomes the left-hand side element and a new element appears as the right-hand side element.

2. Both the line on upper and lower side rotate 45º in an anticlockwise direction in each step.

Hence, option (3) is the correct answer.

The logic followed here is:

1. The shading moves from lower-left corner to the upper-right corner of the quadrilateral.

2) The elements move to the adjacent side (of the quadrilateral) in a clockwise direction.

3. The element that reaches the Left-hand side position gets replaced by a new symbol.

From above logic we get,

Hence, option (1) is the next image in the series.

The pattern followed is,

1. Small square changes its position in an anticlockwise direction.

2. The water image of the arrow sign changes its position in a clockwise direction.

3. The circle moves adjacent to the corner of the square in an anticlockwise direction.

From above logic we get,

Hence, option (1) is the correct answer.

The logic followed here is:

All desert are found in the same country/continent, but 'Karakum' is not found in Argentina.

Additional Information

 

Hence, the correct answer is "Karakum - Argentina".

The figure which will complete the pattern of the question figure is given below:

Hence, the correct answer is "Option (3)".

The figure which will complete the pattern of question figure is given below:

<br>

Hence, the correct answer is "Option (4)".

The figure which complete the pattern of question figure is given below:

Hence, the correct answer is "option (3)".

The position values of the letters according to the English alphabet series.

LOGIC: The letters shifted by +1, +2, +3, +4, +5, +6, and +7.

The pattern followed here is:

Similarly,

Hence, the correct answer is "DGUXFOU".

The position of letter according to the English alphabet series:

The pattern followed here is:

Similarly,

Hence, the correct answer is "CMOST".

The correct answer is- 'with.'

Key Points

 

• From the given options, 'with' is the most appropriate answer to fill in the blank.
• As we can understand from the sentence that she was pleased with something.
• 'Delighted with' means to please someone with something, such as a gift. (किसी को किसी चीज से खुश करना।)
• Example: He was delighted with the gift.
• So option 1 is the most appropriate answer. As it fits with the context of the sentence.

The correct sentence is: She was delighted with as well as surprised at her friend's fluke.

Additional Information 

• Let's understand the meaning of the word fluke:
• Fluke is a noun and it means an unexpected stroke of good luck. (सौभाग्य का अप्रत्याशित आघात।)
• Example: Their victory was a bit of a fluke.

The correct answer is 'doing something risky'. 

Key Points

• Let's learn the meaning of the given idiom:
• Walking on thin ice: to be doing something that is dangerous or involves risks
• Example: I had walked on thin ice and, so far, got away with it.​
• The most appropriate meaning of the given idiom is 'doing something risky'.

Therefore, the correct answer is Option 4.

<br>

We can easily learn this idiom by visualizing a man walking on the surface of very thin ice to go to the other side. He is taking a very high risk because the ice surface can break at any instance.

• Walking on thin ice: कुछ ऐसा करना जो खतरनाक हो या जिसमें जोखिम शामिल हों
• Example: I had walked on thin ice and, so far, got away with it.
• दिए गए मुहावरे का सबसे उपयुक्त अर्थ 'doing something risky' है।
• हम एक आदमी को एक तरफ से दूसरी तरफ जाने के लिए बहुत पतली बर्फ की सतह पर चलने की कल्पना करके इस मुहावरे को आसानी से सीख सकते हैं। वह बहुत अधिक जोखिम ले रहा है क्योंकि बर्फ की सतह किसी भी समय टूट सकती है।

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

Explanation   

• The phrase "Round peg in a square hole" means a misfit, one not suited for the job or position at hand or a person who does not fit in or is not comfortable with others or in a particular situation; someone who is unsuited to a certain task, position, situation, or group of people.

• From the options, it is clear that "A misfit" is the most suitable substitute.

• Hence, we can say that "A misfit" is the correct answer.
  

• Examples of "Round peg in a square hole" in a sentence:

• "I was kind of a round peg in a square hole who just didn't quite seem to mould with everything."

• He said Mr Page told him, "Son, you're a round peg in a square hole".

The correct answer is- 'Collect.'

Key Points

• Let's understand the meaning of the given word:
• Garner is a verb and it means to collect something, usually after much work or with difficulty*.* (कुछ इकट्ठा करना, आमतौर पर बहुत काम के बाद या कठिनाई से।)
• Example: Coppola garnered several Oscars for his movie, "The Godfather."
• By the meaning and example, we can say that 'Collect' is a similar word for 'Garner.'

Hence option 1 is the correct answer.

Additional Information

• Antonyms of the given word Garner are:
• Spend, Disperse, Waste
• Let's understand the meaning of the given options:
• Collect: Bring together (एक साथ लाना)
• Dispel: Cause to separate and go in different directions (अलग होने और अलग-अलग दिशाओं में जाने का कारण)
• Disperse: Make a group split (एक समूह को विभाजित करना)
• Dissipate: Move away from each other (���क दूसरे से दूर हट जाना)

The correct answer is option 1: Privilege.

 

• The word 'Prerogative'  means 'a right or privilege exclusive to a particular individual or class'.

• The synonyms of the given word 'Prerogative' are "appanage, birthright, right".

• The antonyms of the given word 'Prerogative' are "prohibition, ban, obligation, forbidding".

• The meaning of the given word 'Prerogative' is 'Privilege' since both have a similar meaning.

• The word 'Privilege' means a special right, advantage, or immunity granted or available only to a particular person or group.

• ​​​Let's look at the meaning of the other given options-
  

 

• Examples of 'Prerogative' in a sentence:
• Education was once the prerogative of the elite.
• President may use his prerogative of mercy towards a criminal.

The correct answer is 'Privilege'.

The correct answer is- 'Normal'

Key Points 

The word 'erratic' means 'deviating from the norm.' (आदर्श से भटक रहा है।) The meanings of the words are:

• Normal: conforming to a standard; usual, typical, or expected. (एक मानक के अनुरूप; सामान्य, विशिष्ट, या अपेक्षित)
• Aberration: abnormality (abnormality)
• Arcade: a covered passage with arches along one or both sides. (एक या दोनों तरफ मेहराब के साथ एक ढका हुआ मार्ग।)
• Sarcastic: marked by or given to using irony in order to mock or convey contempt. (उपहास या अवमानना ​​व्यक्त करने के लिए विडंबना का उपयोग करके चिह्नित या दिया गया।)

Hence, 'Normal' is the correct answer.

The correct answer is- 'Happy.'

Key Points

• Let's understand the meaning of the given word:
• Wrath is a noun and it means extreme anger*.* (अत्यधिक क्रोध।)
• Example: The people feared the wrath of God.
• By the meaning and example, we can say that 'Happy' is the opposite word for 'Wrath.'

Hence option 2 is the correct answer.

Additional Information

• Synonyms of the given word Wrath are:
• Fury, Rage, Hate
• Let's understand the meaning of the given options:
• Happy: Marked by joy or pleasure (खुशी से चिह्नित)
• Anger: The state of being angry (क्रोधित होने की अवस्था)
• Rage: A feeling of intense anger (तीव्र क्रोध की भावना)
• Fury: A feeling of intense anger (तीव्र क्रोध की भावना)

The correct answer is 'downgraded.'

Key Points

• The given passage is saying that the Asian Development Bank has reduced India’s economic growth forecast to a lower level.
• Therefore, here we need a word whose meaning is similar to 'reduced to a lower level.'
• ​अतः यहाँ हमें एक ऐसे शब्द की आवश्यकता है जिसका अर्थ 'reduced to a lower level' के समान हो।
• Let us see the meanings of the given words in the options:
• Uplifted: raised the level of; improve. (स्तर बढ़ाना; सुधारना।)
• Projected: estimated or forecast (something) on the basis of present trends or data. (वर्तमान रुझानों या आंकड़ों के आधार पर अनुमान या पूर्वानुमान।)
• Downgraded: reduced to a lower grade, rank, or level of importance. (निम्न ग्रेड, रैंक, या महत्व के स्तर तक कम करना।)
• Upgraded: raised (something) to a higher standard, in particular, improved (equipment or machinery) by adding or replacing components. (एक उच्च स्तर पर (कुछ) बढ़ाना, विशेष रूप से घटकों को जोड़कर या बदलकर (उपकरण या मशीनरी) में सुधारना।)
• Therefore, out of these, the word close to 'reduced to a lower level' is 'downgraded.'
• Hence, the correct answer for the blank (1) is 'downgraded.'
• Correct phrase: The Asian Development Bank has downgraded India’s economic growth .............

<br>

Additional Information

Let us see the synonyms of the given words:

The correct answer is 'into.'

Key Points

• The meaning of the phrase 'take into account' is to consider or remember something when judging a situation. ('Take into account' वाक्यांश का अर्थ किसी स्थिति को देखते हुए किसी चीज़ पर विचार करना या याद रखना है।)
• Example: A good architect takes into account the building's surroundings.
• ​Therefore, the preposition 'into' should be used to make the sentence grammatically correct.
• Hence, the correct answer for the blank (2) is 'into.'
• ​​​Correct phrase: This downgrade was done taking into account the adverse impact .............

​

Additional Information

Let us discuss some other phrases with 'take':

The correct answer is 'ended.'

Key Points

• As the second half of the given passage is in the Past Tense, therefore the first part must also be in the Past Tense.
• The option 'will end' is incorrect because it is in the Future tense.
• The option 'ends' is incorrect because it is in the Present tense.
• The option 'ended' is correct because it is in the Past tense.
• The option 'will ended' is incorrect because it is grammatically incorrect.
• Hence, the correct form of tenses, 'ended' should be used to make the sentence grammatically correct.
• Hence, the correct answer is 'ended.'
• ​​Correct phrase: *..........*fiscal year which ended in March 2021ed, India’s GDP growth recovered to 1.6%.

<br>

Additional Information

• We use 'can' and 'could' to talk about a skill or ability.
• Example: My grandfather could play golf very well.
• ​We can use verbs such as 'must' or 'should' to say when something is necessary or unnecessary or to give advice.
• Example: Children must do their homework.
  

Hinglish

• चूंकि दिए गए गद्यांश का दूसरा भाग Past Tense में है, इसलिए पहला भाग भी Past Tense में ही होना चाहिए।
• विकल्प  'will end' गलत है क्योंकि ये Future tense में है।
• विकल्प 'ends' गलत है क्योंकि ये Present tense में है।
• 'Ended' विकल्प सही है क्योंकि ये Past tense में है।
• विकल्प 'will ended' गलत है क्योंकि यह व्याकरणिक रूप से गलत है।
• इसलिए, काल के सही रूप, 'ended' का उपयोग किया जाना चाहिए, वाक्य को व्याकरणिक रूप से सही बनाने के लिए।
• हम एक कौशल या क्षमता के बारे में बात करने के लिए 'can'और 'could' का उपयोग करते हैं।
• Example: My grandfather could play golf very well.
• हम कुछ आवश्यक या अनावश्यक है, कहने के लिए या सलाह देने के लिए 'must' या  'should' का उपयोग कर सकते हैं।
• Example: Children must do their homework

The correct solution is option 4 i.e. Paths are steep and uneven

Key Points 

• The passage talks about mountain climbing.
• Let us refer to this line from the passage, "Paths are usually very steep. Some mountain sides are straight up and down, so it may take many hours to climb as little as one hundred feet".
• From the above line, we get to know that mountains are not straight roads they are very uneven and have many ups and downs.
• So, it becomes very difficult to climb on them due to their steepness.

From the above lines, we can infer that it difficult to climb mountains because paths are steep and uneven.

The correct solution is option 1 i.e. To get the feeling of freedom.

Key Points 

• The passage talks about mountain climbing.
• Let us refer to this line from the passage, "They had wanted to get that feeling of freedom that one has, after climbing a difficult mountain."
• Once we climb a mountain and reach the top we get a wonderful feeling. We feel god-like. It's a great feeling of freedom.
• The prisoners before going to jail wanted that feeling of freedom one last time.

From the above lines, we can infer that two Italian prisoners escaped from the camp and climbed on the top of Mount Kenya to get the feeling of freedom.

The correct solution is option 4 i.e. None of these.

Key Points 

• The passage talks about mountain climbing.
• The given line from the passage, "It is a wonderful feeling to reach the top of a mountain after climbing for hours and maybe, even days."
• It refers to the feeling you get when you look down the top of the mountain after days of climbing. It's a god-like feeling.
• All the given options are wrong so its non of the above.

The correct answer is 1 i.e. beneficial.

Important Points

• Here, the word 'activity' is a noun.
• In the given sentence, an adjective should be used to describe the noun 'activity'.
• Let us explore the given options:
• Beneficial is an adjective meaning helpful or good to something or someone.
• Benefitial has the spelling error.
• Benefit is a noun meaning help or an advantage from something.
• Benefitted is the past participle of Benefit.
• Thus, the correct answer is option 1.
• ​Complete Sentence: Exercise can be a very beneficial activity as long as you do not overdo it.

​

Additional Information

• An adjective is a word that modifies a noun or noun phrase or describes its referent. Its semantic role is to change the information given by the noun.

The correct answer is- 'the more better you get'

Key Points 

• The error is in part 3 as ‘more’ used before ‘better’ is grammatically incorrect.
• The correct statement would be:
• The more you work hard, the better you get. More is a comparative form of many and much.
  

 Therefore, the correct sentence is: The more you work hard, the better you get. Usage of more for better understanding: ​

The correct answer is- 'He would succeeds.'

Key Points 

• In the given sentence, the error lies in the first part of the sentence.
• The sentence uses the verb 'succeeds', which is incorrect, as it is used with the modal verb 'would' here.
• To make the sentence correct replace the verb 'succeeds' with 'succeed'.
• Thus option 1 is the correct answer.

The correct sentence is: He would succeed in his efforts only if he tried hard.

Additional Information 

• Let's learn more about the conditional sentence:
• The correct way to structure second conditional sentences is to use the simple past tense in the if-clause and an auxiliary modal verb (e.g., could, should, would, might) followed by the first form of the verb in the main clause.
• Example: He would visit a doctor if he got sick.

The correct answer is 'c)'.

Key Points

• The error lies in Part c) of the sentence.
• In Part c) of the given sentence, the use of the conjunction 'or' is wrong.
• We use 'rather than' to give more importance to one thing when two alternatives or preferences are being compared.
• After rather /other, the conjunction than should be used.
• Example: Maybe he'd rather listen than talk.
• Hence, the conjunction 'or' in Part c) of the sentence should be replaced by the conjunction 'than' to make the sentence grammatically correct.
• Hence, the correct answer is 'c)'.

​Correct sentence:* I would rather buy a scooter than a cycle.*

<br>

Additional Information

• We use rather as a degree adverb (rather cold, rather nice).
• We also use it to express alternatives and preferences (green rather than blue, coffee rather than tea, slowly rather than quickly).
• We use rather to give emphasis to an adjective or adverb.
• It has a similar meaning to quite when quite is used with gradable words.
• Example: No, I’m rather busy, in fact.
  

               I’m afraid I behaved rather badly.

The correct answer is '​a mention of you.'

Key Points

• The meaning of the idiom 'make mention of' is to talk about, write about, or refer to (something or someone) especially in a brief way : to mention. (मुहावरा 'make mention of' का अर्थ विशेष रूप से संक्षिप्त तरीके से बात करना, लिखना, या (कुछ या किसी को) संदर्भित करना है: उल्लेख करना।)
• Example: She made mention of their contributions.
• ​The correct answer is '​a mention of you.'
• Correct answer: He made a mention of you.

Additional Information

• Let us discuss other idioms with 'make':
  

 

The correct answer is barking up the wrong tree.

Key Points

• The correct idiom that fits the blanks is barking up the wrong tree, that means be pursuing a mistaken or misguided line of thought or course of action.
• In the given sentence, the second subject I of the sentence states his innocence as he is wrongly accused.
• The usage of the noun innocent after the conjunction because that is used to show a reason hints that this idiom contextually fits the blank.

Hence, the complete sentence is: Hey, man, you are absolutely barking up the wrong tree here because I’m innocent.

​

Additional Information

• Let's look at the meaning of other idioms:

• | Idiom | Meaning | Example | | --- | --- | --- | | a devil's advocate | someone who pretends, in an argument or discussion, to be against an idea or plan that a lot of people support. | I don't really believe all that - I was just playing devil's advocate. | | an eye candy | someone or something that is attractive but not very interesting or useful. | Most of the images on the website are not more than eye candy. | | set the bar | to set a high/low standard for something | They have set the bar high in terms of what people expect from them. |

• The origin of the idiom barking up the wrong tree dates back to early 1800s America when hunting with packs of dogs was very popular. The term was used literally at first, when wily prey animals such as raccoons would trick dogs into believing they were up a certain tree when in fact, they had escaped. Thus, dogs barking at the base of an empty tree were said to be barking up the wrong tree.

The correct answer is: Alphabetism

Key Points

• The meaning of the given expression is:
• How the spoken sounds of an alphabet are expressed.
• This expression is known as alphabetism.
• Let's consider the words given in other options:
• Alphabet: It refers to all the sounds used in a particular language, put in a systematic order.
• Alphabetic : It is used for the order of the sounds of some particular language.
• Alphabeticiation: It is not a correct word.
• Thus the correct answer is: Alphabetism

Mistake Points

• An alphabet means any one letter.
• Alphabet means the complete set of sounds of a particular language such as A to Z

The correct answer is: Amateur

Key Points

• We are to find the word for a person who does not do things for the sake of money but does only for pleasure.
• Let's consider the usage of the given words to find the correct word:

 

 

• Thus the correct answer is: Amateur

Important Points

• All the words given in options other than 'Amateur' are the people who work for the sake of money.

The correct answer is Option C.

Key Points 

• “Hold all the aces” means to be in a strong position when you’re competing with someone. (जब आप किसी के साथ प्रतिस्पर्धा कर रहे हों तो एक मजबूत स्थिति में होना)
• Option 1 “Keep abreast” means to keep up with the current news that is happening around.(वर्तमान समाचारों के साथ बने रहने के लिए जो आसपास हो रहा है) For eg:
• To pass the exam you need to keep abreast of the news.
• Option 2 “Have the floor” means to turn to speak in the meeting.(बैठक में बोलने के लिए मुड़ें) For eg:
• It was Rahul’s turn to have the floor but he was so nervous that he forgot the opening speech.
• Option 3: “Trump Card” means an advantage that likely makes you succeed. (एक फायदा जो आपको सफल बनाता है) For eg:
• India has a trump card that’s why Pakistan doesn’t want to fight with us.
• Option 4 “In the pickle” means to get into trouble. (समस्या में पड़ने के लिए)

Hence option 3 is correct because it is a synonym of hold all the aces.

The correct answer is- 'in.'

Key Points

• The correct option to fill in the blank is 'in.' As we know, the proverb is "A bird in the hand is worth two in the bush."
• Now let's understand the meaning of the given proverb:
• it is better to have something small but certain rather than the mere possibility of a  greater one. (किसी बड़े की संभावना मात्र के बजाय कुछ छोटा लेकिन निश्चित होना बेहतर है।)
• Example: I might have got a better offer if I had waited for some more time, but I decided to take the one I had. After all, a bird in the hand is worth two in the bush.

Thus option 2 is the correct answer.

Additional Information

• Now let's learn about the origin of the given maxim:
• This proverb has its origins in medieval falconry, where a bird (falcon) in hand was more valuable than two in the bush. The earliest known usage in English is in the 15th century in “The Life of St Katherine” by John Capgrave. (इस कहावत की उत्पत्ति मध्ययुगीन बाज़ को पालने की विद्या के दौरान हुई है, जहाँ हाथ में एक पक्षी (बाज़) झाड़ी में दो पक्षियों से अधिक मूल्यवान था। अंग्रेजी में सबसे पहला ज्ञात उपयोग जॉन कैपग्रेव द्वारा "द लाइफ ऑफ सेंट कैथरीन" में 15 वीं शताब्दी में है।)

The correct answer is- 'take over.'

Key Points

• The meaning of 'take over' is to take control. (नियंत्रण लेना।) 
• Example: Germany took over several other countries during World War II.
• ​By the given sentence we can understand that Ankit will take control when Rahul will retire.
• Thus option 2 is the correct answer.

The correct sentence is: Ankit will take over as managing director when Rahul retires.

Additional Information

• Now let's learn the meaning of the other given options:
• Take away - Of or involving food to be taken and eaten off the premises (परिसर से बाहर ले जाने और खाने के लिए भोजन शामिल करना)
• Take up - Fill space or time (स्थान या समय भरना)
• Take down - Destroy (a building) so as to make nearly level the ground (एक इमारत को नष्ट करना ताकि जमीन को लगभग समतल कर दिया जा सके)

The correct option is 'To'

Key Points

• To

1. Used to indicate the place, person, or thing that someone or something moves toward, or the direction of something
2. Used to indicate a limit or an ending point
3. Used to indicate relationship:

          so here to will be used to indicate relationship (to my boss) hence option 2 is correct.

Given:

The average score in 10 matches = 50

The average score in the first 6 matches = 40

Formula used:

Average = Sum of observation/Total number of observation

Calculation:

The total score in all matches = 10 × 50

⇒ 500 runs

The total score in the first 6 matches = 6 × 40

⇒ 240 runs

The total score in the last 4 matches = 500 - 240

⇒ 260 runs

The average score in the last 4 matches = 260/4

⇒ 65

∴ The average score in the last 20 matches is 65 runs.

Given:

Speed of a train is 40% more than the speed of a car.

P and Q are 280 km apart from each other

Formula used:

Speed = Distance/Time

Distance = Speed × Time

Calculation:

Let the speed of the car be y km/hr

According to the question, the Speed of a train is 40% more than the speed of a car. Therefore,

Speed of the train = y × (140/100) = 7y/5       

Time is taken by car to covered  280 km = 280/y

Since the train stops for 60 minutes, i.e. 1 hr.

Time is taken by Train = [280/(7y/5)] + 1    

Since, both time are equal, then

1400/7y + 1 = 280/y

⇒ 200/y + 1 = 280/y

⇒ 200 + y = 280

⇒ y = 80 km/hr

Speed of train = 7y/5 = (7 × 80)/5 = 112 km/hr

∴ The speed of the train is 112 km/hr.

Given:

A dishonest seller his goods at cost price but uses a weight of 980 gms for 1 kg.

Formula:

Gain % = [(Error)/(True value – Error)] × 100

Calculation:

According to the question,

Seller uses a weight of 980 gms for 1 kg.

1 kg = 1000 gms.

Error in weight = 1000 – 980 = 20 gms.

According to the formula,

Gain % = [20/(1000 – 20)] × 100

⇒ (20/980) × 100

⇒ 2.04%

∴ The gain percent is 2.04%.

Given:

Compound interest = Rs. 2100

Rate of interest = 10%

Time = 2 years

Formula used:

C.I. = P{(1 + R/100)T - 1)}

S.I. = PRT/100

Where, 

C.I. = Compound interest, S.I. = Simple interest

P = Principal, R = Rate of interest, T = Time

Calculation:

C.I. = P{(1 + R/100)T - 1)}

⇒ 2100 = P{(1 + 10/100)2 - 1)}

⇒ 2100 = P{(11/10)2 - 1)}

⇒ 2100 = P{21/100}

⇒ P = Rs. 10000      ---(1)

S.I. = PRT/100

⇒ S.I. = (10000 × 10 × 2)/100

⇒ S.I. = Rs. 2000

∴ The simple interest is Rs. 2000.

Alternate Method

When the rate is calculated at compound interest, the total increase in the rate in two years 

X + Y + XY/100

⇒ 10 + 10 + 100/100

⇒ 21%

According to the question

⇒ 21% ≡ Rs. 2100

⇒ 1% ≡ Rs. 100      ---(1)

When the rate is calculated at simple interest, the total rate in two years is 20%.

Now, From equation (1)

⇒ 1% ≡ Rs. 100

⇒ 20% ≡ Rs. 2000

∴ The simple interest is Rs. 2000.

Given:

5 × 5 + 2 × 5 × x + 2 × 2 = 49

Formula used:

(a + b)2 = a2 + 2ab + b2 

Calculation:

5 × 5 + 2 × 5 × x + 2 × 2 = 49

⇒ 5 × 5 + 2 × 5 × x + 2 × 2 = 7²

⇒ 5 × 5 + 2 × 5 × x + 2 × 2 = (5 + 2)²

⇒ 52 + 2 × 5 × x + 22 = 5² + 2 × 5 × 2 + 2²

Comparing both the sides, then we get

x = 2

∴ The value of x is 2.

Shortcut TrickLet the total work be 30 units 

Efficiency of A = 30/10 = 3 units per day 

Efficiency of B = 30/30 = 1 unit per day 

According to the question 

Both started the work together and worked for 2 days 

Work done by (A + B) in 2 days = 2 × (3 + 1) = 8 

Remaining work = 30 - 8 = 22 unit 

The remaining work will be done by B  

Time taken by B to complete remaining work = 22/1 = 22 days 

So, The total time to complete the work by them = 2 + 22 = 24 days

Alternate Method

Given:

A alone can complete the work = 10 days

B alone can complete the work = 30 days

Formula used:

W = T × E

(Where W = Work, T = Time, and E = Efficiency)

Calculation:

Let be assume B did work for X days

⇒ The efficiency of A = 1/10 days

⇒ The efficiency of B = 1/30 days

⇒ 2/10 + X/30 = 1

⇒ {(2 × 3) + X}/30 = 1

⇒ 6 + X = 30

⇒ X = 30 - 6

⇒ X = 24 days

∴ The required result will be 24 days.

Given:

${P \over 4} = {Q \over 5} = {R \over 7}$

Calculation:

Let ${P \over 4} = {Q \over 5} = {R \over 7} = k$

Now, P = 4k, Q = 5k, R = 7k

Then, Q + R - P = 5k + 7k - 4k = 8k

∴​ ${Q + R - P}\over P$ = 8k/4k = 2

Given:

Total students in a School = 820

The ratio of boys and girls is 22 : 19

Calculations:

 22 : 19 = 22x : 19x

⇒ 41x = 820

⇒ x = 20

Boys = 22x = 22 × 20 = 440

Girls = 19x = 19 × 20 = 380

Total girls after 2 years = 380 × 110/100 × 150/100 = 627

Ratio of boys and girls after 2 years = 440/627 = 40/57

∴ Ratio of boys and girls after 2 years is 40/57.

Given:

Simple interest  in 3 years = Rs. 600

The simple interest on the sum is two times the sum after 5 years.

Formula used:

Simple Interest = (P × R × T)/100

Amount = Sum + Interest

Calculation:

Let the principal be Rs. 'x'.

⇒ Amount after 5 year = 2x

So, the simple interest after 5 years is (2x - x) = Rs. ' x'.

Simple Interest = (P × R × T)/100

⇒ x = (x × R × 5)/100 

⇒ R = 20x/x

⇒ R = 20%

Simple Interest = (P × R × T)/100

⇒ 600 = (x × 20 × 3)/100

⇒ x = (600 × 100)/(60)

⇒ x = Rs. 1000

∴ The sum is Rs. 1000.

Given

A person covers (1/5)th of the distance with the speed = 20 km/h

A person covers (1/4)^th of the distance with the speed = 10 km/hr

Formula used

Average Speed = Total Distance/Total time taken

Calculation

Let the total distance = LCM (4, 5) = 20 unit

A person cover distance with  speed of 20 km/hr = 1/5 × 20 = 4 unit

A person cover distance with speed of 10 km/hr = 1/4 × 20 = 5 unit

Remaining Distance = 20 - 4 - 5 = 11 unit

Average Speed = 20 unit/[(4/20) + (5/10) + (11/60)]

⇒ 20 unit × 60/(12 + 30 + 11) = 22.64 km/hr

∴ The required answer is 22.64 km/hr

Given:

Cost price = Rs. 400 + Rs. 110 = Rs. 510

Discount = 15%

Profit = 25%

Formula used:

Marked Price(MP) = Selling Price(SP) +  Discount

SP = Cost Price(CP) × (100 +  profit%)/100

Calculation:

According to the question = Rs. 510

SP = 510 × (125/100) = Rs. 637.5

Let marked price be 100%

S.P = 100 - 15 = 85%

85% = 637.5

⇒ 100% = 637.5 × (100/85)

⇒ 100% = Rs. 750

∴ The marked price will be Rs. 750.