UPSC Prelims PYQs with explanations
Real questions from official papers, mapped to syllabus topics. Attempt each one; the answer and the reason appear instantly.
| 7B | 10A | 3C |
|---|---|---|
| 3C | 9B | 6A |
| 10A | 13C | ? |
Following is a matrix of certain entries. The entries follow a certain trend row-wise. Choose the missing entry (?) accordingly.
Answer (c) & explanation
The missing entry is 3B (c). Step 1: look at the numbers in each row. The third number is the second minus the first: 10 − 7 = 3 and 9 − 3 = 6. So in the last row, 13 − 10 = 3. Step 2: look at the letters. Each row uses A, B and C once each. The last row already has A and C, so the missing letter is B. Step 3: put them together: 3B. Option (a), 9B, gets the number wrong. Options (b) 3A and (d) 3C repeat a letter already in the row.
Tip: in matrix puzzles, split the entry into parts (number and letter) and solve each part on its own. Check your rule on every row before trusting it.
Answer as per the official UPSC answer key.
Consider the following addition problem : 3P + 4P + PP + PP = RQ2; where P, Q and R are different digits. What is the arithmetic mean of all such possible sums ?
Answer (c) & explanation
The mean of the possible sums is 202 (c). Step 1: write out the sum: 3P + 4P + PP + PP = (30 + P) + (40 + P) + 11P + 11P = 70 + 24P. Step 2: the sum RQ2 ends in 2. So 24P must end in 2, which happens when P = 3 (sum 142) or P = 8 (sum 262). In both, P, Q and R are different digits. Step 3: the mean is (142 + 262) ÷ 2 = 202. Options (a), (b) and (d) do not match.
Tip: in digit puzzles, start with the units place. The last digit of a sum usually narrows the choices to one or two.
Answer as per the official UPSC answer key.
The money multiplier in an economy increases with which one of the following?
Answer (c) & explanation
The money multiplier rises with a stronger banking habit (c). The money multiplier shows how much broad money banks create from each rupee of reserve money. When people keep more money in banks and less as cash, banks have more to lend, and each loan comes back as a fresh deposit to be lent again. So option (c) is right. Options (a) and (b) are wrong: a higher CRR or SLR locks up funds, leaving less to lend, so the multiplier falls. Option (d) is wrong: population size alone does not change the multiplier.
Notice the formula in its simplest form: multiplier = 1 ÷ reserve ratio. Broad money is M3; reserve money (M0) is the RBI's own money base.
Answer as per the official UPSC answer key.
Who among the following is associated with ‘Songs from Prison’, a translation of ancient Indian religious lyrics in English?
Answer (c) & explanation
Gandhi is linked with "Songs from the Prison" (c). In Yeravda jail in 1930, Gandhi translated Sanskrit hymns and lyrics from the Ashram Bhajanavali into English. John S. Hoyland put them into verse, and they came out in 1934 as "Songs from the Prison". Option (a) is wrong: Tilak wrote the Gita Rahasya in Mandalay jail. Option (b) is wrong: Nehru wrote The Discovery of India in Ahmednagar Fort jail. Option (d) is wrong: Sarojini Naidu wrote her own poems, such as The Golden Threshold, and was called the "Nightingale of India".
Notice that Gandhi also wrote From Yeravda Mandir there. His autobiography, The Story of My Experiments with Truth, was written in Gujarati.
Answer as per the official UPSC answer key.
We adopted parliamentary democracy based on the British model, but how does our model differ from that model?
- 1. As regards legislation, the British Parliament is supreme or sovereign but in India, the power of the Parliament to legislate is limited.
- 2. In India, matters related to the constitutionality of the Amendment of an Act of the Parliament are referred to the Constitution Bench by the Supreme Court.
Select the correct answer using the code given below.
Answer (c) & explanation
Both statements are correct (c). Statement 1 is right: Britain has no single written constitution that limits Parliament, so its Parliament is sovereign and can pass any law. India's Parliament works within a written Constitution, limited by Fundamental Rights, the federal division of powers and judicial review. Even its power to amend is limited by the basic structure doctrine (Kesavananda Bharati, 1973). Statement 2 is right: under Article 145(3), a substantial question on interpreting the Constitution goes to a bench of at least five judges, the Constitution Bench.
Notice that India's model blends British parliamentary sovereignty with American judicial supremacy. Other British features India kept: cabinet government, the speaker, and a nominal head of state.
Answer as per the official UPSC answer key.
The number 3798125P369 is divisible by 7. What is the value of the digit P ?
Answer (b) & explanation
P is 6 (b). Step 1: a test for 7 (it also works for 11 and 13): from the right, split the number into groups of three digits and add and subtract them in turn. 3798125P369 splits into 37 | 981 | 25P | 369. Step 2: 369 − 25P + 981 − 37 = 1313 − (250 + P) = 1063 − P. This must be divisible by 7. Step 3: 1063 = 7 × 151 + 6. So 1063 − P is divisible by 7 when P = 6. Options (a), (c) and (d) leave remainders.
Tip: the alternating three-digit sum works because 1001 = 7 × 11 × 13. It is the fastest check for large numbers.
Answer as per the official UPSC answer key.
Consider two Statements and a Question :
Statement-1 : Priya is 4 ranks below Seema and is 31st from the bottom.
Statement-2 : Ena is 2 ranks above Seema and is 37th from the bottom.
Question : What is Seema's rank from the top in the class of 40 students ?
Which one of the following is correct in respect of the Statements and the Question ?
Answer (c) & explanation
Either statement alone is enough (c). Step 1: in a class of 40, rank from top = 40 − rank from bottom + 1. Step 2: Statement-1: Priya is 31st from the bottom, so she is 40 − 31 + 1 = 10th from the top. Seema is 4 ranks above her, so 6th. Step 3: Statement-2: Ena is 37th from the bottom, so 4th from the top. Seema is 2 ranks below her, so again 6th. Each statement alone gives the answer. Options (a) and (b) wrongly say one is not enough. Option (d) wrongly says both are needed.
Tip: in data sufficiency, test each statement on its own first. Only combine them if neither works alone.
Answer as per the official UPSC answer key.
An amount of money was distributed among A, B and C in the ratio p : q : r. Consider the following statements :
- 1. A gets the maximum share if p is greater than (q + r).
- 2. C gets the minimum share if r is less than (p + q).
Which of the above statements is/are correct ?
Answer (a) & explanation
Only statement 1 is correct (a). Step 1: if p is greater than q + r, then p is more than half the total. So p is bigger than both q and r, and A gets the maximum share. Statement 1 is true. Step 2: r less than p + q only means r is less than half. That does not make r the smallest. Step 3: try 1 : 5 : 4. Here r = 4 is less than 6, but A gets the least, not C. So statement 2 is false, and options (b), (c) and (d) fail.
Tip: to disprove a "general" statement, find one counter-example with small numbers.
Answer as per the official UPSC answer key.
Consider the following kinds of organisms :
- 1. Copepods
- 2. Cyanobacteria
- 3. Diatoms
- 4. Foraminifera
Which of the above are primary producers in the food chains of oceans?
Answer (b) & explanation
Cyanobacteria and diatoms are primary producers (b). Primary producers make their own food by photosynthesis, forming the base of the food chain. Item 2 is right: cyanobacteria (blue-green algae) photosynthesise and also fix nitrogen. Item 3 is right: diatoms are phytoplankton with glass-like silica shells, and they produce much of the world's oxygen. Item 1 is wrong: copepods are tiny crustaceans that eat phytoplankton, so they are consumers. Item 4 is wrong: foraminifera are shelled protists that mostly feed on other organisms.
Notice that marine phytoplankton produce about half of Earth's oxygen. Foraminifera shells pile up on the ocean floor and help scientists study past climates.
Answer as per the official UPSC answer key.
Consider the following statements :
- 1. The Global Ocean Commission grants licences for seabed exploration and mining in international waters.
- 2. India has received licences for seabed mineral exploration in international waters.
- 3. ‘Rare earth minerals’ are present on seafloor in international waters.
Which of the statements given above are correct?
Answer (b) & explanation
Statements 2 and 3 are correct (b). Statement 1 is wrong: licences for the deep seabed beyond national limits come from the International Seabed Authority (Kingston, Jamaica), set up under UNCLOS. The Global Ocean Commission was only an advocacy group. Statement 2 is right: India holds ISA contracts for polymetallic nodules in the Central Indian Ocean Basin (since 1987 as a pioneer investor) and for polymetallic sulphides on the Indian Ocean ridge. Statement 3 is right: seabed nodules and muds contain rare earth elements.
Notice India's Deep Ocean Mission (2021) and Samudrayaan, which plans to send people to 6,000 m in the submersible Matsya-6000.
Answer as per the official UPSC answer key.
Which one of the following factors constitutes the best safeguard of liberty in a liberal democracy?
Answer (d) & explanation
Separation of powers is the best safeguard of liberty (d). Liberty is safest when no single organ holds all power, so each can check the others. That is Montesquieu's case for the separation of powers in The Spirit of the Laws (1748). Option (a) is a trap: a "committed" judiciary, meaning one committed to the government of the day, as debated in India in the 1970s, is a danger to liberty. Option (b) is wrong: centralising power threatens liberty. Option (c) is wrong: an elected government can still become oppressive, the "tyranny of the majority".
Notice that India has a functional separation of powers rather than a strict one; it is part of the basic structure. The US Constitution follows it most strictly, with checks and balances.
(a) sounds good, but "committed judiciary" was a 1970s phrase for a judiciary loyal to the government.
Answer as per the official UPSC answer key.
Images of consonants of the English alphabet (Capitals) are observed in a mirror. What is the number of images of these which do not look like their original shapes ?
Answer (b) & explanation
14 consonants look different in a mirror (b). Step 1: a capital letter looks the same in a mirror if it has a vertical line of symmetry. Step 2: among the 21 consonants, these have one: H, M, T, V, W, X, Y. That is 7 letters. Step 3: the rest look different: 21 − 7 = 14. Option (a), 13, wrongly includes another letter. Options (c) and (d) miss some symmetric letters.
Tip: the vowels A, I, O and U are also symmetric, but the question asks only about consonants. There are 26 letters, 5 vowels, so 21 consonants. Memorise "AHIMOTUVWXY" as the mirror-same capitals.
Answer as per the official UPSC answer key.
Consider two Statements and four Conclusions given below. You have to take the Statements to be true even if they seem to be at variance from the commonly known facts. Read all Conclusions and then decide which of the given Conclusion(s) logically follows/follow from the Statements, disregarding the commonly known facts.
Statement-1 : Some greens are blues.
Statement-2 : Some blues are blacks.
Conclusion-1 : Some greens are blacks.
Conclusion-2 : No green is black.
Conclusion-3 : All greens are blacks.
Conclusion-4 : All blacks are greens.
Which one of the following is correct ?
Answer (d) & explanation
None of the four conclusions follows (d). Step 1: "some greens are blues" and "some blues are blacks" give no sure link between greens and blacks. The blues that are black may not be the green ones. Step 2: so "some greens are blacks" (1), "no green is black" (2), "all greens are blacks" (3) and "all blacks are greens" (4) are each possible, but none is certain. Step 3: options (a), (b) and (c) pair conclusions that do not follow. Conclusions 1 and 2 do form an "either-or" pair, but no option offers "either 1 or 2".
Tip: two "some" statements never give a definite conclusion. Draw the circles in two ways; if the answer changes, nothing follows.
1 and 2 form an 'either–or' pair, but no option offers 'either 1 or 2'.
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Answer as per the official UPSC answer key.
Consider the following statements :
- 1. The Governor of the Reserve Bank of India (RBI) is appointed by the Central Government.
- 2. Certain provisions in the Constitution of India give the Central Government the right to issue directions to the RBI in public interest.
- 3. The Governor of the RBI draws his power from the RBI Act.
Which of the above statements are correct?
Answer (c) & explanation
Statements 1 and 3 are correct (c). The RBI Act, 1934 creates the Reserve Bank and its Central Board. Statement 1 is right: under Section 8 of the Act, the Central Government appoints the Governor and Deputy Governors. Statement 3 is right: the Governor's powers flow from the RBI Act. Statement 2 is wrong: the government's power to give directions to the RBI "in the public interest", after consulting the Governor, is in Section 7 of the RBI Act, not in the Constitution. The Constitution does not mention the RBI at all.
Notice that Section 7 was reportedly discussed for the first time in 2018, during differences between the government and the RBI. The RBI was nationalised in 1949, and it began work in 1935, with headquarters first in Calcutta.
statement 2 is true in substance but names the wrong source. Always check where a power comes from.
One trap spotted is one mark saved. The PYQ Book lines up every trap UPSC has set, so you walk in prepared. Try the free sample
Answer as per the official UPSC answer key.
In the first quarter of seventeenth century, in which of the following was/were the factory/factories of the English East India Company located?
- 1. Broach
- 2. Chicacole
- 3. Trichinopoly
Select the correct answer using the code given below.
Answer (a) & explanation
Only Broach had an English factory then (a). After Jahangir's farman in 1613, won after the English beat the Portuguese at Swally, the English East India Company set up its first permanent factory at Surat. In the 1610s it opened factories at Broach, Agra, Ahmedabad and Burhanpur, so item 1 is right. Item 2 is wrong: Chicacole (Srikakulam) on the Andhra coast came under English influence only in the 18th century, as part of the Northern Circars. Item 3 is wrong: Trichinopoly became important only in the Carnatic wars of the 1740s–50s.
Notice Sir Thomas Roe, James I's ambassador to Jahangir (1615–19). The English got Bombay as dowry in 1661 and founded Madras in 1639.
Answer as per the official UPSC answer key.
Bollgard I and Bollgard II technologies are mentioned in the context of
Answer (b) & explanation
Bollgard refers to genetically modified crops (b). Bollgard is Monsanto's (now Bayer's) Bt cotton. Bollgard I carries the cry1Ac gene from the soil bacterium Bacillus thuringiensis, and Bollgard II adds cry2Ab. These genes make toxins that kill the bollworm, a major cotton pest. It is not about clonal propagation (a), growth substances (c) or biofertilisers (d).
Notice that Bt cotton, approved in 2002, is India's only commercially approved GM crop, though GM mustard (DMH-11) got environmental release approval in 2022. Pink bollworm has developed resistance, weakening Bt cotton. The GEAC under the Environment Ministry approves GM crops. India released two genome-edited rice varieties in 2025.
Answer as per the official UPSC answer key.
Which one of the following in Indian polity is an essential feature that indicates that it is federal in character?
Answer (a) & explanation
An independent judiciary is the essential federal feature (a). A federation divides power between the Union and the States. That division needs an independent umpire to settle disputes between them and to interpret the Constitution, so the independence of the judiciary is an essential federal feature. In India, the Supreme Court settles Centre–State disputes under Article 131. Option (b) can exist in a unitary state with regional seats. Option (c) is a matter of politics, not structure. Option (d) concerns rights, which unitary states also protect.
Notice the other federal features: a written Constitution, division of powers (Seventh Schedule), bicameralism and a rigid amendment process. India is often called "quasi-federal", after K.C. Wheare.
Answer as per the official UPSC answer key.
You are given two identical sequences in two rows :
| Sequence-I : | 8 | 4 | 6 | 15 | 52.5 | 236.25 |
|---|---|---|---|---|---|---|
| Sequence-II : | 5 | A | B | C | D | E |
What is the entry in the place of C for the Sequence-II ?
Answer (c) & explanation
The entry at C is 9.375 (c). Step 1: find the rule in Sequence-I. Each term is the one before multiplied by 0.5, 1.5, 2.5, 3.5, 4.5 in turn. The multiplier grows by 1 each step. Step 2: the two sequences are "identical", so Sequence-II follows the same rule, only starting from 5. Step 3: 5 × 0.5 = 2.5, then 2.5 × 1.5 = 3.75, then 3.75 × 2.5 = 9.375. Option (a), 2.5, is the first step and option (b), 5, is the start. Option (d), 32.8125, is a later term.
Tip: when a sequence grows unevenly, divide each term by the one before it. The pattern often hides in these ratios.
Answer as per the official UPSC answer key.
Consider the following multiplication problem :
(PQ) × 3 = RQQ, where P, Q and R are different digits and R ≠ 0.
What is the value of (P + R) ÷ Q ?
Answer (b) & explanation
(P + R) ÷ Q is 2 (b). Step 1: Q × 3 must end in Q. Only Q = 0 (0 × 3 = 0) and Q = 5 (5 × 3 = 15) work. Step 2: if Q = 0, then P0 × 3 = R00, which no single digit P can give. So Q = 5. Step 3: try P5 × 3 until the result ends in 55: 85 × 3 = 255. So P = 8 and R = 2. Then (P + R) ÷ Q = 10 ÷ 5 = 2. Option (d) is wrong because the data do fix the answer.
Tip: look for digits that repeat themselves when multiplied (0, 1, 5, 6). They often unlock such puzzles quickly.
Answer as per the official UPSC answer key.
With reference to Indian economy, demand-pull inflation can be caused/increased by which of the following?
- 1. Expansionary policies
- 2. Fiscal stimulus
- 3. Inflation-indexing wages
- 4. Higher purchasing power
- 5. Rising interest rates
Select the correct answer using the code given below.
Answer (a) & explanation
Items 1, 2 and 4 cause demand-pull inflation (a). Demand-pull inflation comes from too much spending chasing too few goods. Item 1 is right: expansionary policies, such as low rates, raise demand. Item 2 is right: a fiscal stimulus, such as tax cuts or more public spending, raises demand. Item 4 is right: higher purchasing power lets people buy more. Item 3 is wrong: indexing wages to inflation raises firms' costs, which is cost-push inflation. Item 5 is wrong: rising interest rates make borrowing dearer and reduce demand, so they curb inflation.
Notice cost-push causes: dearer oil, supply shocks, and higher wages. A wage–price spiral happens when rising prices push wages up, which push prices up again.
wage indexation does raise prices, but through costs. Sort each cause into demand side or cost side.
Answer as per the official UPSC answer key.