CSAT (Paper II): previous-year questions
1280 real UPSC Prelims questions (2011–2026) with the official answer and a clear explanation. 400 of them came in the last five papers.
How often UPSC asks this
Questions per year, counted from the official papers.
Subtopics
Arrangements, ranking, ordering and puzzles
142 questions
Clocks and calendars
5 questions
Coding-decoding, series, patterns, cubes, dice and visual reasoning
110 questions
Communication, interpersonal skills and decision-making
10 questions
Counting, permutations, combinations and probability
1 questions
Directions, blood relations and Venn diagrams
60 questions
General English: grammar, vocabulary and comprehension
20 questions
General Hindi: grammar, vocabulary, dialects and comprehension
25 questions
Geometry and mensuration
26 questions
Number system and basic algebra (divisibility, HCF/LCM, remainders, digits, equations)
196 questions
Percentages, profit and loss, discount, simple and compound interest
47 questions
Ratio, proportion, averages, mixtures and alligation
47 questions
Syllogisms, statements and conclusions, assumptions and arguments
89 questions
Time and work; pipes and cisterns
2 questions
Time, speed and distance; trains, boats and streams; races
48 questions
Attempt the questions
Newest papers first. Tap an option; the answer and the reason appear instantly.
Read the passage
Sport is not just about winning medals or getting jobs through a sports quota. Today’s generation is struggling with issues like depression and anxiety. Parents often say that their children are inactive and rarely leave the house. Sport can help tackle these problems. From sport you can learn time management, fitness, teamwork, coordination, and so much more. We need to develop a culture in which sport is seen as a way of life—a path to building a healthier, happier society.
Which of the following conclusions are valid?
- 1. Sport is more than just games; it is a way of life.
- 2. Sport can help mitigate the problems of seclusion among the young.
- 3. Earning laurels in sport can help one secure a job on the basis of an assigned quota.
- 4. Standard corporate sector skills cannot be learnt through sport.
Select the answer using the code given below.
Answer (d) & explanation
Conclusions 1, 2 and 3 are valid (d). Step 1: conclusion 1 matches the last line: sport should be seen as "a way of life". Step 2: conclusion 2 follows from parents saying children are inactive and "rarely leave the house", which sport can help fix. Conclusion 3 follows from the mention of "getting jobs through a sports quota". Step 3: conclusion 4 says corporate skills cannot be learnt through sport. But the passage says sport teaches time management and teamwork, so 4 contradicts it. Options (a), (b) and (c) fail.
Tip: a conclusion that contradicts the passage fails at once. The Khelo India and Fit India movements promote sport as a way of life.
Answer as per the official UPSC answer key.
A person saves 10% of his salary every month. If his salary increases by 12% and the expenditure increases by 10%, then what will be the change in his saving per month?
Answer (b) & explanation
His saving rises by 30% (b). Step 1: take salary = 100. He saves 10%, so saving = 10 and expenditure = 90. Step 2: new salary = 112 (12% more). New expenditure = 99 (10% more than 90). Step 3: new saving = 112 − 99 = 13. Saving goes from 10 to 13, a rise of 3 on 10 = 30%. Options (a), (c) and (d) fail.
Tip: take 100 for the salary and split it into saving and spending. Small percentage changes in big amounts can cause large changes in the small leftover.
the saving is a small base. A 2% gap between the two growth rates becomes a 30% change in saving.
Answer as per the official UPSC answer key.
| List-I (Barrier to communication) | List-II (Example) |
|---|---|
| A. Semantic | 1. Lack of feedback |
| B. Cognitive | 2. Misunderstanding the meaning of a word |
| C. Organisational | 3. Fear of social stigma |
| D. Affective | 4. Information overload |
Match List-I with List-II and select the answer using the code given below the Lists :
Answer (d) & explanation
The match is A-2, B-4, C-1, D-3 (d). Step 1: semantic barriers concern the meaning of words, so misunderstanding a word (A-2). Step 2: cognitive barriers concern the mind's ability to process, so information overload (B-4). Step 3: organisational barriers come from the system, like lack of feedback channels (C-1). Affective barriers come from feelings, such as fear of social stigma (D-3). Options (a), (b) and (c) mismatch.
Tip: link each word to its root: semantic = meaning, cognitive = thinking, affective = emotion, organisational = structure. This quickly solves communication-barrier matching.
Answer as per the official UPSC answer key.
What is the minimum number of times one needs to measure to get 298 litres of water from a tank, if the measuring cylinders have capacities 1 litre, 6 litres, 25 litres and 100 litres?
Answer (b) & explanation
The minimum is 5 measures (b). Step 1: adding only, the best is 2 × 100 + 2 × 25 + 8 × 6 = 298, which needs 12 measures. That is not an option, so think about taking water out too. Step 2: 298 = 3 × 100 − 2 × 1. Pour in 100 litres three times, then remove 1 litre twice: 5 measures. Step 3: could 4 work? 3 × 100 leaves 2 litres to remove, and no single cylinder holds 2 litres, so 4 is impossible. Options (a), (c) and (d) fail.
Tip: when adding gives too many steps, try overshooting and subtracting. Measuring questions often allow both pouring in and taking out.
Answer as per the official UPSC answer key.
Read the passage
Cattle from the nearby villages came to the common ground to graze, and there was still a cool freshness in the air. Hori took several deep breaths and thought of sitting down for a while, since he’d be dying of heat in the scorching ‘loo’ wind the rest of the day. A number of farmers were eager to lease this bit of land and had offered a good price, but Rai Sahib—God bless him—had plainly told them it was reserved for grazing and would not be relinquished for any price. If he’d been one of those selfish Zamindars, he’d have said the cattle could go to hell, that there was no reason for him to miss the chance to make a little money. But the Rai Sahib still held to the old values, feeling that any landlord who didn’t look after his tenants was less than human.
Which of the following conclusions is/are correct?
- 1. All landlords essentially have some goodness trapped within them.
- 2. The common grazing grounds of a village are intended for use by the cattle of that village.
- 3. Landlords who believe in tradition tend to be more concerned about their tenants.
- 4. Winds later in the day tend to be cooler post the hot winds of the morning.
Select the answer using the code given below.
Answer (c) & explanation
Only conclusion 3 is correct (c). Step 1: Rai Sahib "held to the old values", believing a landlord who did not look after his tenants was "less than human". So tradition-minded landlords care more for tenants (3). Step 2: conclusion 1 says all landlords have goodness; but the passage mentions "selfish Zamindars". Conclusion 2 says the grazing land is for the cattle of that village; but cattle came "from the nearby villages". Step 3: conclusion 4 says winds get cooler later; but Hori expects the scorching "loo" for the rest of the day. So options (a), (b) and (d) fail.
Tip: check small details like "nearby villages" and time of day. This passage is from Premchand's novel Godaan (1936).
Answer as per the official UPSC answer key.
Question : X receives three coins of different denominations : 1, 2, 5, 10 and 20. If the total amount received by X is m, does X receive a coin of denomination 5?
Statement I : m is not a prime number.
Statement II : The sum of the digits of m is greater than 5.
Answer (a) & explanation
Statement II alone is enough; Statement I alone is not (a). Step 1: three different coins from 1, 2, 5, 10, 20 give ten totals. With a 5: 8, 16, 17, 26, 27, 35. Without a 5: 13, 23, 31, 32. Step 2: Statement I (m not prime): 8, 16, 26, 27, 35 have a 5, but 32 (2 + 10 + 20) does not. Mixed answers, so I fails. Step 3: Statement II (digit sum above 5): 8, 16, 17, 26, 27, 35 qualify, and every one has a 5. (13, 23, 31, 32 have digit sums 4, 5, 4, 5.) So II answers "yes". Options (b), (c) and (d) fail.
Tip: when cases are few, list them all. Then check each statement against the full list.
don't assume both statements are needed. Listing all ten cases takes thirty seconds and settles it.
Answer as per the official UPSC answer key.
P, Q, R, S and T are ranked 1 to 5 (not necessarily in that order). The rank of P is 4, the rank of Q is not 5, the rank of R is 1, the rank of S is not 2, the rank of T is not 3. Then which of the following is/are correct?
- I. If the rank of S is 3, then that of T is 2.
- II. If the rank of Q is 3, then that of T is 5.
Select the answer using the code given below.
Answer (d) & explanation
Neither statement is correct (d). Step 1: P = 4 and R = 1 are fixed. Ranks 2, 3 and 5 remain for Q, S and T, with rules: Q is not 5, S is not 2, T is not 3. Step 2: statement I: if S = 3, then Q and T share 2 and 5. Q cannot be 5, so Q = 2 and T = 5, not 2. I is wrong. Step 3: statement II: if Q = 3, then S and T share 2 and 5. S cannot be 2, so S = 5 and T = 2, not 5. II is wrong. Options (a), (b) and (c) fail.
Tip: fix the known ranks first, then apply each "if" condition and let the "not" rules decide the rest. Write the small table on paper.
Answer as per the official UPSC answer key.
An alloy P contains 20% copper and 80% zinc by weight. Another alloy Q contains 60% copper and 40% zinc by weight. A third alloy R is to be prepared from P and Q so that it contains equal amount of copper and zinc. In what ratio, amounts of P and Q be mixed in order to get R?
Answer (a) & explanation
P and Q must be mixed in the ratio 1 : 3 (a). Step 1: "equal copper and zinc" means R is 50% copper. Step 2: use alligation on copper: P has 20%, Q has 60%, and the mix needs 50%. P : Q = (60 − 50) : (50 − 20) = 10 : 30. Step 3: simplify to 1 : 3. Check: 1 kg P gives 0.2 kg copper; 3 kg Q gives 1.8 kg; total 2 kg copper in 4 kg = 50% ✓. Option (b) reverses the ratio. Options (c) and (d) fail.
Tip: in alligation, the amount of each item is the distance of the other item from the mean. Always check with a quick calculation.
Answer as per the official UPSC answer key.
Read the passage
Sport is not just about winning medals or getting jobs through a sports quota. Today’s generation is struggling with issues like depression and anxiety. Parents often say that their children are inactive and rarely leave the house. Sport can help tackle these problems. From sport you can learn time management, fitness, teamwork, coordination, and so much more. We need to develop a culture in which sport is seen as a way of life—a path to building a healthier, happier society.
Which of the following statements is/are correct?
- 1. Parents are not encouraging enough when it comes to children playing sport.
- 2. Participation in sporting activities can help develop life skills.
- 3. Sport as a way of life can help evolve the very nature of society itself.
Select the answer using the code given below.
Answer (b) & explanation
Statements 2 and 3 are correct (b). Step 1: statement 2 matches the line that sport teaches "time management, fitness, teamwork, coordination". These are life skills. Step 2: statement 3 matches the closing line: sport as a way of life is "a path to building a healthier, happier society". Step 3: statement 1 blames parents for not encouraging sport. The passage only says parents report that children are inactive; it never blames them. So options (a), (c) and (d) fail.
Tip: do not turn a reporter into a culprit. When the passage quotes someone's complaint, it does not mean that person caused the problem.
Answer as per the official UPSC answer key.
P has a son and a daughter. S is the mother of T. S is R's spouse. Q and R are children of P. Then how is Q related to S?
Answer (d) & explanation
Q is the sister of S's husband (d). Step 1: S is T's mother, so S is a woman. S is R's spouse, so R is a man. Step 2: Q and R are P's children, and P has one son and one daughter. R is the son, so Q is the daughter. Step 3: Q is R's sister, and R is S's husband. So Q is the sister of the husband of S (her sister-in-law). Options (a), (b) and (c) give wrong relations.
Tip: in blood-relation puzzles, first fix genders from clues like "mother" and "spouse". Then draw a small family tree.
Answer as per the official UPSC answer key.
You are required to design a 'questionnaire' to be filled on-location by visitors, based on the following objective while writing a report :
"To determine the feasibility of setting up a family-oriented vacation resort in the vicinity of a lake destination in the mountains"
Which of the following heads would you include in the questionnaire to make it most appropriate for your purpose?
- 1. Size of family
- 2. Budget
- 3. Number of earners in the family
- 4. Food allergies and dietary restrictions
Select the answer using the code given below.
Answer (c) & explanation
Heads 1 and 2 only should be included (c). Step 1: the goal is to test the feasibility of a family resort: will there be demand, and at what price? Step 2: family size (1) shows the kind of rooms needed. Budget (2) shows what visitors will spend, which sets pricing. Both bear directly on feasibility. Step 3: number of earners (3) is personal, and its effect already shows in the budget. Food allergies (4) matter for running the resort later, not for deciding whether to build it. So options (a), (b) and (d) fail.
Tip: include only questions that serve the stated objective. Extra personal questions also reduce response rates in surveys.
Answer as per the official UPSC answer key.
There are four types of weights, namely 1 kg, 2 kg, 5 kg and 10 kg. What is the maximum number of different ways one can measure 20 kg, if at least eight but not more than eleven weights of 1 kg are to be used while measuring?
Answer (b) & explanation
There are 8 ways (b). Step 1: with eight 1 kg weights, we need 12 kg from 2, 5 and 10 kg weights (no more 1s): 10 + 2, 5 + 5 + 2, and six 2s: 3 ways. Step 2: with nine 1 kg, we need 11 kg: only 5 + 2 + 2 + 2: 1 way. Step 3: with ten 1 kg, we need 10 kg: 10, 5 + 5, five 2s: 3 ways. With eleven 1 kg, we need 9 kg: 5 + 2 + 2: 1 way. Total = 3 + 1 + 3 + 1 = 8. Options (a), (c) and (d) miscount.
Tip: fix one variable at a time and count the rest. Here, fixing the number of 1 kg weights keeps the cases clean.
an odd remainder needs exactly one 5 (two or more would be too much or leave an odd gap).
Fell for this one? Most aspirants do. The PYQ Book puts every UPSC trap side by side, so the pattern finally clicks. Try the free sample
Answer as per the official UPSC answer key.
Read the passage
Cattle from the nearby villages came to the common ground to graze, and there was still a cool freshness in the air. Hori took several deep breaths and thought of sitting down for a while, since he’d be dying of heat in the scorching ‘loo’ wind the rest of the day. A number of farmers were eager to lease this bit of land and had offered a good price, but Rai Sahib—God bless him—had plainly told them it was reserved for grazing and would not be relinquished for any price. If he’d been one of those selfish Zamindars, he’d have said the cattle could go to hell, that there was no reason for him to miss the chance to make a little money. But the Rai Sahib still held to the old values, feeling that any landlord who didn’t look after his tenants was less than human.
Which of the following statements are not correct?
- 1. The landholdings of Rai Sahib were currently not being used for farming.
- 2. Temperamentally, Rai Sahib was as greedy as other landlords.
- 3. It cannot be ascertained that Rai Sahib could have made some money by leasing out the grazing land.
- 4. It may be asserted that Rai Sahib valued his tenants and wanted to protect their livelihood.
Select the answer using the code given below.
Answer (d) & explanation
Statements 1, 2 and 3 are not correct (d). Step 1: statement 1 says his land was not used for farming. The passage says only "this bit of land" was kept for grazing; nothing about the rest. So 1 overreaches. Step 2: statement 2 calls him greedy like others. But he refused a good price, unlike "selfish Zamindars". So 2 is wrong. Step 3: statement 3 says his possible earnings cannot be ascertained. But farmers "had offered a good price", so he clearly could have earned. So 3 is wrong. Statement 4, that he valued his tenants, is correct. Options (a), (b) and (c) fail.
Tip: in "not correct" questions, find the one true statement first; the rest are your answer.
Answer as per the official UPSC answer key.
Question : For two distinct real numbers x and y, which of them is bigger?
Statement I : x2 < y < 1
Statement II : y < √x < 1
Answer (d) & explanation
Even both statements together are not enough (d). Step 1: together they give x² < y < √x, with √x < 1, so x is between 0 and 1. Step 2: test x = 1/4. Then x² = 1/16 and √x = 1/2, so y can be anywhere between 0.0625 and 0.5. Step 3: y = 0.1 is smaller than x (0.25); y = 0.4 is bigger than x. Both fit, so we cannot say which is bigger. Options (a), (b) and (c) fail.
Tip: for numbers between 0 and 1, x² < x < √x. So x itself sits inside the range for y, and y can fall on either side. Test with x = 1/4; it gives clean numbers.
Answer as per the official UPSC answer key.
Two identical straight rods are painted in five distinct colours so that each of them gets divided into five equal parts along the length. In one of them, the portions are marked P1, P2, P3, P4 and P5 (not necessarily in that order) whereas in the other, they are marked Q1, Q2, Q3, Q4 and Q5 (not necessarily in that order). When the rods are kept parallel to each other side by side, P1 and Q3 match, P4 matches Q1 or Q2, and Q4 matches P3 or P5. If Q3 and Q5 are adjacent, which of the following is/are possible?
- I. Q3 is marked at the middle portion of the straight rod.
- II. P2 is marked at one of the extreme portions of the straight rod.
Select the answer using the code given below.
Answer (c) & explanation
Both statements are possible (c). Step 1: "possible" needs just one arrangement that fits all rules. Number the portions 1 to 5 on each rod. Step 2: try rod Q: Q1, Q2, Q3, Q5, Q4 and rod P: P2, P4, P1, P5, P3. Step 3: check the rules: P1 and Q3 both sit at position 3 ✓; P4 is at 2, beside Q2 ✓; Q4 is at 5, beside P3 ✓; Q3 and Q5 are adjacent ✓. In this arrangement, Q3 is in the middle (I) and P2 is at an end (II). So both are possible, and options (a), (b) and (d) fail.
Tip: for "possible" questions, build one valid example. For "must be true", you would need to check every case.
'possible' asks for one example, not for something that is always true.
Answer as per the official UPSC answer key.
A is a 2-digit number with different digits. B is also a 2-digit number and is obtained by reversing the digits of A. If A – B is a multiple of 27, where A > B, how many such different A's are possible?
Answer (b) & explanation
Nine such numbers are possible (b). Step 1: let A = 10a + b and B = 10b + a, with a > b. Then A − B = 9(a − b). Step 2: for this to be a multiple of 27, a − b must be a multiple of 3: 3, 6 or 9. Step 3: a − b = 3: b = 1 to 6 (A = 41, 52, 63, 74, 85, 96): 6 numbers. a − b = 6: b = 1 to 3 (A = 71, 82, 93): 3. a − b = 9 needs b = 0, making B a one-digit number (09), so it is not allowed. Total = 9. Options (a), (c) and (d) fail.
Tip: A number minus its reverse is always 9 × (digit difference). B must also be two-digit, so the units digit of A cannot be 0.
B must also be a 2-digit number, so 90 is out.
Answer as per the official UPSC answer key.
A toy T jumps forward or backward. In each forward jump, it moves 5' forward whereas in each backward jump, it moves 2' backward. If in 31 jumps, T moves exactly 15' forward, then what is the difference of the number of forward and backward jumps?
Answer (d) & explanation
The difference is 9 jumps (d). Step 1: let f be forward jumps and b backward jumps. Total jumps: f + b = 31. Net movement: 5f − 2b = 15. Step 2: put b = 31 − f: 5f − 2(31 − f) = 15, so 5f − 62 + 2f = 15, giving 7f = 77 and f = 11. Then b = 20. Step 3: difference = 20 − 11 = 9. Check: 5 × 11 − 2 × 20 = 55 − 40 = 15 ✓. Options (a), (b) and (c) fail.
Tip: two unknowns need two equations: one for the count and one for the total effect. Always check your answer in both.
Answer as per the official UPSC answer key.
How many three-digit numbers can be expressed as an integral power of 2?
Answer (c) & explanation
Three three-digit numbers are powers of 2 (c). Step 1: keep doubling from 1: 1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024. Step 2: only 128 (2⁷), 256 (2⁸) and 512 (2⁹) have three digits. 1024 (2¹⁰) has four. Step 3: so the count is 3. Options (a), (b) and (d) miscount.
Tip: learn powers of 2 up to 2¹⁰ = 1024. Between any two powers of 10 there are always three or four powers of 2, since 2¹⁰ is about 10³.
Answer as per the official UPSC answer key.
With reference to 'circular letters', which of the following statements is/are correct?
- 1. Circular letters are usually addressed to a group of people.
- 2. Non-standard and customized content is typical of circular letters.
- 3. Circular letters are used to intimate appraisals and increments of employees within organisations.
- 4. Circular letters are less cost-effective than personalised and specific recipient-directed letters.
Select the answer using the code given below.
Answer (d) & explanation
Only statement 1 is correct (d). Step 1: a circular letter sends the same message to many people, so it is addressed to a group (1 correct). Step 2: statement 2 is wrong: circular content is standard, not customised. Statement 3 is wrong: appraisals and increments are personal, so they go in individual letters. Step 3: statement 4 is wrong: circulars are more cost-effective, since one text serves everyone. So options (a), (b) and (c) fail.
Tip: think of a school circular about a holiday: one message, many readers, low cost. Anything personal or private does not go by circular.
Answer as per the official UPSC answer key.
A cut on a solid object divides the object into two parts where the new surfaces thus produced are plane. On the other hand, one single cut can be used to cut more than one object at a time. In an experiment, the total number of pieces produced by applying n cuts is denoted by xₙ. The experiment is performed on a solid cube where pieces remain unmoved after each cut. In this experiment, if after the third cut, the pieces are identical, then which of the following is not a possible value for x₄?
Answer (a) & explanation
16 is not possible (a). Step 1: three plane cuts that leave identical pieces can give 4 slabs (all parallel), 6 equal pieces (two parallel plus one across), or 8 small cubes (one in each direction). Step 2: a fourth cut can add at most one piece for each piece it passes through. From 4 slabs: 5 to 8 pieces. From 6 pieces: up to 12. From 8 cubes: a single plane can pass through at most 7 of the 8 small cubes, so at most 15. Step 3: so 5, 8 and 12 are possible, but 16 would need the cut to split all 8 cubes, which no plane can do. Options (b), (c) and (d) are possible values.
Tip: a plane can never cut all 8 octants of a cube at once; it misses at least one.
Answer as per the official UPSC answer key.