UPSC Prelims PYQs with explanations
Real questions from official papers, mapped to syllabus topics. Attempt each one; the answer and the reason appear instantly.
Read the passage
For two or three generations past, ever-increasing numbers of individuals have been living as workers merely, not as human beings. An excessive amount of labour is rule today in every circle of society, with the result that man’s spiritual element cannot thrive. He finds it very difficult to spend his little leisure in serious activities. He does not want to think; or he cannot even if he wants to. He seeks not self-improvement, but entertainment which would enable him to be mentally idle and to forget his usual activities. Therefore, the so-called culture of our age is dependant more on cinema than on theatre, more on newspapers, magazines and crime stories than on serious literature.
The passage is based on the idea that
Answer (b) & explanation
The passage is based on the idea that overstrain is the great evil of our age (b). Step 1: the passage says "an excessive amount of labour" is the rule today. Step 2: everything else follows from this: man's spiritual side cannot grow, he has little leisure, and he seeks only entertainment. So overwork is the root idea. That is (b). Step 3: option (a), man should not work hard, overstates it; the problem is excess. Options (c) and (d) are effects of overwork, not the main idea.
Tip: separate the root cause from its effects. The base idea is the cause the author keeps returning to.
Answer as per the official UPSC answer key.
Read the passage
How best can the problems of floods and droughts be addressed so that the losses are minimal and the system becomes resilient? In this context, one important point that needs to be noted is that India gets ‘too much’ water (about 75% of annual precipitation) during 120 days (June to September) and ‘too little’ for the remaining 245 days. This skewed water availability has to be managed and regulated for its consumption throughout the year.
Which one of the following best reflects the practical, rational and lasting solution?
Answer (d) & explanation
The lasting solution is buffer stocking of water through dams and recharging aquifers (d). Step 1: the passage says India gets about 75% of its rain in 120 days (June to September) and too little in the other 245 days. Step 2: the problem is timing, so water must be stored for year-round use. Dams store surface water and recharged aquifers store groundwater. That is (d). Step 3: canals (a) and river interlinking (c) mainly move water across places, not across seasons. Option (b), changing crops, does not store water.
Tip: match the solution to the problem. A time problem (seasons) needs storage; a place problem needs transfer.
Answer as per the official UPSC answer key.
Consider the following countries :
- 1. Azerbaijan
- 2. Kyrgyzstan
- 3. Tajikistan
- 4. Turkmenistan
- 5. Uzbekistan
Which of the above have borders with Afghanistan ?
Answer (c) & explanation
Tajikistan, Turkmenistan and Uzbekistan border Afghanistan (c). Afghanistan's northern neighbours are Turkmenistan, Uzbekistan and Tajikistan, with much of the border along the Amu Darya river. Afghanistan also borders Iran (west), Pakistan (east and south) and China, through the narrow Wakhan Corridor. Item 2 is wrong: Kyrgyzstan is cut off from Afghanistan by Tajikistan. Item 1 is wrong: Azerbaijan lies across the Caspian Sea, in the Caucasus.
Notice that the Wakhan Corridor separates Tajikistan from Pakistan-occupied Kashmir. India's land route to Afghanistan is blocked by Pakistan, so India uses Chabahar port in Iran. The Taliban returned to power in August 2021.
Answer as per the official UPSC answer key.
According to Kautilya’s Arthashastra, which of the following are correct ?
- 1. A person could be a slave as a result of a judicial punishment.
- 2. If a female slave bore her master a son, she was legally free.
- 3. If a son born to a female slave was fathered by her master, the son was entitled to the legal status of the master’s son.
Which of the statements given above are correct ?
Answer (b) & explanation
Statements 2 and 3 are correct (b). The Arthashastra has a detailed section on dasas (slaves). Statement 2 is right: a female slave who bore her master a son became legally free. Statement 3 is right: such a son was given the legal status of the master's son. Statement 1 is not accepted by the key: the text speaks of people bound because of a fine or debt who work it off and can be redeemed; it protects even them, and says an Arya cannot be made a slave forever.
Notice how unusual this is for an ancient text. Kautilya fined masters who sold an Arya child, abused a slave or kept a slave woman in sexual servitude. The text also says the mleccha may sell children, but never an Arya.
Many guides print (d) here. The official key is (b).
Answer as per the official UPSC answer key.
Which one of the following statements about Sangam literature in ancient South India is correct ?
Answer (b) & explanation
Sangam poets knew the varna system (b). Option (b) is right: Sangam poems use terms for the varnas, such as arasar (rulers), anthanar (Brahmins) and vaishiyar (traders), though Tamil society was mostly arranged by tinai (landscape) and kudi (clan). Option (a) is wrong: the poems are full of material life: trade, Yavana ships, ports like Muziris and Puhar, food and crafts. Option (c) is wrong: the Puram poems praise the warrior ethic, and hero-stones (nadukal) honour dead warriors. Option (d) is wrong: the poems treat magic, omens and spirits as real, not irrational.
Notice the two themes: Akam (inner, love) and Puram (outer, war and kings). The Tolkappiyam is the oldest Tamil grammar.
Answer as per the official UPSC answer key.
The increase in the price of a certain item was 25%. Then the price was decreased by 20% and then again increased by 10%. What is the resultant increase in the price?
Answer (b) & explanation
The resultant increase is 10% (b). Step 1: start with a price of ₹ 100. A 25% rise makes it ₹ 125. Step 2: a 20% cut on 125 is ₹ 25, bringing it to ₹ 100. Step 3: a 10% rise on 100 makes it ₹ 110. From ₹ 100 to ₹ 110 is a rise of 10%. Option (d), 15%, wrongly adds 25 − 20 + 10. Options (a) and (c) are other miscalculations.
Tip: multiply the factors: 1.25 × 0.8 × 1.1 = 1.1. A 25% rise followed by a 20% cut always cancels out exactly.
(d) 15% just adds 25 − 20 + 10. Each change works on the new price.
Answer as per the official UPSC answer key.
Read the passage
If presents bring less thrill now that we are grown up, perhaps it is because we have too much already; or perhaps it is because we have lost the fullness of the joy of giving, and with it the fullness of the joy of receiving. Children’s fears are poignant, their miseries are acute, but they do not look too forward nor too far backward. Their joys are clear and complete, because they have not yet learnt always to add ‘but’ to every proposition. Perhaps we are too cautious, too anxious, too sceptical. Perhaps some of our cares would shrink if we thought less about them and entered with more single-minded enjoyment into the happiness that come our way.
With reference to the passage, which one of the following statements is correct?
Answer (b) & explanation
The correct statement is that there can be more than one reason adults feel less thrilled by presents (b). Step 1: the author offers two "perhaps" reasons: we have too much already, or we have lost the full joy of giving. Step 2: more than one possible reason means (b). Step 3: option (a) says adults can never be thrilled. But the passage says "less thrill", not none. Option (c) is wrong because the author does suggest reasons. Option (d), less capacity for love, is not said.
Tip: "perhaps ... or perhaps ..." signals several possible reasons. "Less" thrill never means "no" thrill.
Answer as per the official UPSC answer key.
With reference to the "G20 Common Framework", consider the following statements :
- 1. It is an initiative endorsed by the G20 together with the Paris Club.
- 2. It is an initiative to support Low Income Countries with unsustainable debt.
Which of the statements given above is/are correct ?
Answer (c) & explanation
Both statements are correct (c). Statement 1 is right: the Common Framework for Debt Treatments beyond the DSSI was agreed in November 2020 by the G20 together with the Paris Club of creditor nations. Statement 2 is right: it lets low-income countries with unsustainable debt seek restructuring with all official creditors at one table, including newer lenders such as China that are not in the Paris Club. Zambia, Ghana and Ethiopia applied under it.
Notice its forerunner, the Debt Service Suspension Initiative (DSSI) of 2020, which paused repayments during COVID. India, as G20 president in 2023, pushed for faster debt relief for the Global South. Critics say the framework has been slow.
Answer as per the official UPSC answer key.
Consider the following statements in respect of probiotics :
- 1. Probiotics are made of both bacteria and yeast.
- 2. The organisms in probiotics are found in foods we ingest but they do not naturally occur in our gut.
- 3. Probiotics help in the digestion of milk sugars.
Which of the statements given above is/are correct ?
Answer (c) & explanation
Statements 1 and 3 are correct (c). Probiotics are live, helpful microbes taken in food or supplements. Statement 1 is right: most are bacteria, such as Lactobacillus and Bifidobacterium, and some are yeasts, such as Saccharomyces boulardii. Statement 2 is wrong: the same kinds of microbes live naturally in our gut, as part of the gut microbiome. Statement 3 is right: lactobacilli make the enzyme lactase, which helps digest lactose, the milk sugar, easing lactose intolerance.
Notice the related terms: prebiotics are fibres that feed good bacteria, and synbiotics combine both. Curd (dahi), yoghurt and kefir are common probiotic foods. Probiotics are regulated in India by FSSAI.
Answer as per the official UPSC answer key.
In India, which one of the following compiles information on industrial disputes, closures, retrenchments and lay-offs in factories employing workers ?
Answer (c) & explanation
The Labour Bureau compiles this data (c). The Labour Bureau, under the Ministry of Labour and Employment, with offices at Shimla and Chandigarh, collects statistics on industrial disputes, closures, retrenchments and lay-offs. It also compiles the Consumer Price Index for Industrial Workers (CPI-IW), used to set dearness allowance. Option (a) is wrong: the Central Statistics Office, now part of the NSO, handles national accounts and GDP. Option (b) is wrong: DPIIT compiles the Wholesale Price Index and the index of eight core industries. Option (d) is wrong: NTMIS tracked technical manpower supply.
Notice that the Labour Bureau now also runs the Quarterly Employment Survey. The Periodic Labour Force Survey (PLFS), by contrast, comes from the NSO.
Answer as per the official UPSC answer key.
With reference to Indian history, consider the following texts :
- 1. Nettipakarana
- 2. Parishishtaparvan
- 3. Avadanashataka
- 4. Trishashtilakshana Mahapurana
Which of the above are Jaina texts ?
Answer (b) & explanation
Parishishtaparvan and the Trishashtilakshana Mahapurana are Jaina texts (b). Parishishtaparvan was written by Hemachandra (12th century), the Jain scholar of Gujarat; it tells how Chandragupta Maurya became a Jain and went south with Bhadrabahu. The Trishashtilakshana Mahapurana, by Jinasena and Gunabhadra (9th century), tells the lives of the 63 great men (shalakapurushas) of Jainism. Item 1 is wrong: the Nettipakarana is a Pali Buddhist guide to interpreting the scriptures. Item 3 is wrong: the Avadanashataka is a Sanskrit Buddhist collection of a hundred stories of good deeds. So options (a), (c) and (d) fall.
Notice the shortcut: words like avadana, jataka and nikaya point to Buddhism, while purana with 63 great men, anga or agama usually signal Jainism.
Answer as per the official UPSC answer key.
Read the passage
Natural selection cannot anticipate future environments on the earth. Therefore, the set of existing organisms can never be fully prepared for environmental catastrophes that await life. An outcome of this is the extinction of those species which cannot overcome environmental adversity. This failure to survive, in modern terms, can be attributed to the genomes which are unable to withstand geological vagaries or biological mishaps (infections, diseases and so on). In biological evolution on the earth, extinction of species has been a major feature. The earth may presently have up to ten million species, yet more than 90% of species that have ever lived on the earth are now extinct. Once again, the creationist doctrines fail to satisfactorily address why a divine creator will firstly bother to create millions of species and then allow them to perish. The Darwinian explanation for extinct life is once again simple, elegant and at once convincing—organisms go extinct as a function of environmental or biological assaults for which their inheritance deems them ill-equipped. Therefore, the so-called Darwinian theory of evolution is not a theory at all. Evolution happens—this is a fact. The mechanism of evolution (Darwin proposed natural selection) is amply supported by scientific data. Indeed, to date no single zoological, botanical, geological, paleontological, genetic or physical evidence has refuted either of the central two main Darwinian ideas. If religion is not taken into consideration, Darwinian laws are acceptable just like the laws proposed by Copernicus, Galileo, Newton and Einstein—sets of natural laws that explain natural phenomena in the universe.
According to the passage, natural selection cannot anticipate future environments on the earth as
- 1. species not fully prepared to face the environmental changes that await them will face extinction
- 2. all the existing species would get extinct as their genomes will not withstand biological mishaps
- 3. inability of the genome to withstand environmental changes would result in extinction
- 4. extinction of species is a common feature
Select the correct answer using the code given below.
Answer (c) & explanation
Statements 1, 3 and 4 follow (c). Step 1: the passage says organisms "can never be fully prepared" for coming catastrophes, so unprepared species die out (1). Step 2: it blames genomes that cannot withstand geological vagaries or biological mishaps (3). It calls extinction "a major feature" of evolution (4). Step 3: statement 2 says all existing species will go extinct. The passage never claims this; it only says those that cannot cope die out. So options (a), (b) and (d), which include 2, fail.
Tip: "all" is the giveaway. The passage says more than 90% of species that ever lived are extinct, not that every species will be.
Answer as per the official UPSC answer key.
Read the passage
“The social order is a sacred right which is the basis of all other rights. Nevertheless, this right does not come from nature, and must therefore be founded on conventions.”
With reference to the above passage, which of the following statements is/are correct?
- 1. Conventions are the sources of rights of man.
- 2. Rights of man can be exercised only when there is a social order.
Select the correct answer using the code given below.
Answer (c) & explanation
Both statements are correct (c). Step 1: the passage says the social order is "the basis of all other rights" and it "must be founded on conventions". Step 2: if all rights rest on the social order, and the social order rests on conventions, then conventions are the source of rights (1). Step 3: if the social order is the basis of all rights, rights can work only when a social order exists (2). So options (a), (b) and (d) fail.
Tip: this is Rousseau's Social Contract. Follow the chain: conventions → social order → rights.
Answer as per the official UPSC answer key.
With reference to anti-defection law in India, consider the following statements :
- 1. The law specifies that a nominated legislator cannot join any political party within six months of being appointed to the House.
- 2. The law does not provide any time-frame within which the presiding officer has to decide a defection case.
Which of the statements given above is/are correct?
Answer (b) & explanation
Only statement 2 is correct (b). Statement 1 is wrong: the Tenth Schedule works the other way. A nominated member may join a political party within six months of taking the seat. After that, joining a party leads to disqualification. Statement 2 is right: the Schedule sets no deadline for the presiding officer to decide a defection petition. In Keisham Meghachandra Singh (2020), the Supreme Court said such cases should normally be decided within three months.
Notice that the Tenth Schedule was added by the 52nd Amendment (1985). The 91st Amendment (2003) removed the one-third split exception, leaving only a two-thirds merger. Kihoto Hollohan (1992) made the Speaker's decisions subject to judicial review.
"cannot" for "can". The six-month window is real, but its meaning is reversed.
Answer as per the official UPSC answer key.
“Biorock technology” is talked about in which one of the following situations ?
Answer (a) & explanation
Biorock is used to restore damaged coral reefs (a). Biorock, or mineral accretion, passes a weak, safe electric current through a steel frame placed under the sea. Minerals dissolved in sea water, mainly calcium carbonate, build up on the frame like limestone. Coral pieces fixed to it grow fast and resist stress better. Option (b) describes bio-based building materials. Option (c) describes shale gas survey. Option (d) describes salt licks for wildlife.
Notice that India's Zoological Survey of India, with the Gujarat Forest Department, tried biorock in the Gulf of Kachchh in 2017. Coral reefs face bleaching from warming seas; the world saw its fourth global bleaching event in 2023–24.
Answer as per the official UPSC answer key.
Consider the following statements :
- 1. Bidibidi is a large refugee settlement in north-western Kenya.
- 2. Some people who fled from South Sudan civil war live in Bidibidi.
- 3. Some people who fled from civil war in Somalia live in Dadaab refugee complex in Kenya.
Which of the statements given above is/are correct ?
Answer (c) & explanation
Statements 2 and 3 are correct (c). Statement 2 is right: Bidibidi, one of the world's largest refugee settlements, shelters people who fled the South Sudan civil war that began in 2013. Statement 3 is right: the Dadaab complex in eastern Kenya, near the border, has sheltered Somali refugees fleeing civil war since 1991. Statement 1 is wrong: Bidibidi is in north-western Uganda, in Yumbe district, not in Kenya.
Notice Kenya's other huge camp, Kakuma, in the north-west, which hosts many South Sudanese. Uganda is praised for its open policy: refugees get land to farm and can move and work freely. UPSC uses such places to test both map sense and current affairs.
Answer as per the official UPSC answer key.
The digits 1 to 9 are arranged in three rows in such a way that each row contains three digits, and the number formed in the second row is twice the number formed in the first row; and the number formed in the third row is thrice the number formed in the first row. Repetition of digits is not allowed. If only three of the four digits 2, 3, 7 and 9 are allowed to use in the first row, how many such combinations are possible to be arranged in the three rows?
Answer (c) & explanation
Two arrangements are possible (c). Step 1: the third row is 3 × the first row and must stay a 3-digit number. So the first row is at most 329. Using three of 2, 3, 7, 9, the choices are 237, 239, 273, 279, 293, 297, 327 and 329. Step 2: check that all nine digits 1 to 9 appear once. 273 → 546 → 819 works. 327 → 654 → 981 works. Step 3: the others repeat a digit or produce a 0. So there are 2. Options (a), (b) and (d) miscount.
Tip: first use a size limit (×3 below 1000) to shrink the list. Then test the few candidates left.
Answer as per the official UPSC answer key.
Read the passage
For two or three generations past, ever-increasing numbers of individuals have been living as workers merely, not as human beings. An excessive amount of labour is rule today in every circle of society, with the result that man’s spiritual element cannot thrive. He finds it very difficult to spend his little leisure in serious activities. He does not want to think; or he cannot even if he wants to. He seeks not self-improvement, but entertainment which would enable him to be mentally idle and to forget his usual activities. Therefore, the so-called culture of our age is dependant more on cinema than on theatre, more on newspapers, magazines and crime stories than on serious literature.
Man does not seek self-improvement because he
Answer (d) & explanation
Man does not seek self-improvement because he loves amusement and is mentally idle (d). Step 1: the passage says he seeks "not self-improvement, but entertainment which would enable him to be mentally idle". That is (d). Step 2: option (b) says he has no time. But the passage says he has "little leisure", not none. Step 3: option (a), lack of intellect, is not said; the passage says he does not want to think. Option (c), materialism, is not mentioned.
Tip: "little" is not "no". UPSC often swaps a mild word in the passage for an absolute one in the options.
Answer as per the official UPSC answer key.
If 15 × 14 × 13 × … × 3 × 2 × 1 = 3m × n where m and n are positive integers, then what is the maximum value of m?
Answer (b) & explanation
The maximum value of m is 6 (b). Step 1: count how many times 3 divides 15!. Multiples of 3 up to 15: 3, 6, 9, 12, 15. That gives 5 threes. Step 2: 9 = 3 × 3 has an extra 3. That adds 1 more. Step 3: m = 5 + 1 = 6. Option (c), 5, forgets the extra 3 in 9. Options (a) and (d) miscount.
Tip: to count a prime p in n!, add n/p + n/p² + ... (whole parts only). Here 15/3 + 15/9 = 5 + 1 = 6.
don't forget the extra 3 in 9.
Answer as per the official UPSC answer key.
With reference to India, consider the following statements :
- 1. Monazite is a source of rare earths.
- 2. Monazite contains thorium.
- 3. Monazite occurs naturally in the entire Indian coastal sands in India.
- 4. In India, Government bodies only can process or export monazite.
Which of the statements given above are correct ?
Answer (b) & explanation
Statements 1, 2 and 4 are correct (b). Monazite is a reddish-brown phosphate mineral. Statement 1 is right: it is a major source of rare earth elements such as cerium and neodymium. Statement 2 is right: it contains thorium, a fuel for the third stage of India's nuclear programme. Statement 4 is right: it is a "prescribed substance" under the Atomic Energy Act, 1962, so only government bodies such as IREL (India) Ltd may process or export it. Statement 3 is wrong: it is found in the beach sands of Kerala, Tamil Nadu, Odisha and Andhra Pradesh, not along the entire coast.
Notice that India has among the world's largest thorium reserves. China dominates global rare earth processing, which India wants to reduce through the National Critical Mineral Mission (2025).
Answer as per the official UPSC answer key.