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.
A person walks 100 m straight from his house, turns left and walks 100 m, again turns left and walks 300 m, then turns right and walks 100 m to reach his office. In which direction does he walk initially from his house if his office is exactly in the North-East direction?
Answer (c) & explanation
He first walked South (c). Step 1: test the options. Suppose he starts walking South 100 m. A left turn while facing South points East: 100 m East. Another left points North: 300 m North. A right turn points East: 100 m East. Step 2: net movement: East = 100 + 100 = 200 m; North = 300 − 100 = 200 m. Step 3: equal East and North means exactly North-East. Options (a), (b) and (d) do not give equal East and North parts.
Tip: in direction questions, testing each option is often faster than working backwards. Remember: facing South, your left is East and your right is West.
'left' depends on the way he faces. Facing South, his left is East, not West.
UPSC repeats traps like this year after year. The PYQ Book gathers every trap in one place, so you see them coming. Try the free sample
Answer as per the official UPSC answer key.
Read the passage
As inflation rises, even governments previously committed to budget discipline are spending freely to help households. Higher interest rates announced by central banks are supposed to help produce modest fiscal austerity, because to maintain stable debts while paying more to borrow, governments must cut spending or raise taxes. Without the fiscal backup, monetary policy eventually loses traction. Higher interest rates become inflationary, not disinflationary, because they simply lead governments to borrow more to pay rising debt-service costs. The risk of monetary unmooring is greater when public debt rises, because interest rates become more important to budget deficits.
Which of the following statements best reflects/reflect the most logical and rational inference/inferences that can be made from the passage?
- 1. Central banks cannot bring down inflation without budgetary backing.
- 2. The effects of monetary policy depend on the fiscal policies pursued by the government.
Select the correct answer using the code given below.
Answer (c) & explanation
Both inferences follow (c). Step 1: the key line is "Without the fiscal backup, monetary policy eventually loses traction." Monetary policy means the central bank raising interest rates; fiscal policy means government spending and taxes. Step 2: so rate hikes alone cannot cure inflation if the government keeps spending; the central bank needs budgetary backing (1). Step 3: the passage also says high rates can even turn inflationary when governments simply borrow more. So the effect of monetary policy depends on fiscal choices (2). Options (a), (b) and (d) fail.
Tip: learn the two words: monetary policy = RBI (interest rates, money supply); fiscal policy = government (budget, taxes). In India the RBI's Monetary Policy Committee targets 4% inflation.
Answer as per the official UPSC answer key.
Let X be a two-digit number and Y be another two-digit number formed by interchanging the digits of X. If (X + Y) is the greatest two-digit number, then what is the number of possible values of X?
Answer (d) & explanation
There are 8 possible values of X (d). Step 1: let X = 10a + b, so Y = 10b + a. Then X + Y = 11(a + b). The greatest two-digit number is 99, so 11(a + b) = 99, giving a + b = 9. Step 2: Y must also be a two-digit number, so b cannot be 0. That removes 90. Step 3: X can be 18, 27, 36, 45, 54, 63, 72, 81: 8 values. Option (c), 6, and the others miscount.
Tip: a number plus its reverse is always a multiple of 11; the difference is always a multiple of 9. Watch for hidden conditions like "Y is also two-digit", which rule out a zero digit.
90 looks valid, but its reverse, 09, is not a two-digit number.
Answer as per the official UPSC answer key.
A Question is given followed by two Statements I and II. Consider the Question and the Statements.
There are three distinct prime numbers whose sum is a prime number.
Question : What are those three numbers?
Statement-I : Their sum is less than 23.
Statement-II : One of the numbers is 5.
Which one of the following is correct in respect of the above Question and the Statements?
Answer (a) & explanation
Statement I alone is enough; Statement II alone is not (a). Step 1: if 2 were one of the numbers, the sum of 2 + two odd primes is even and bigger than 2, so not prime. So all three are odd primes. Step 2: statement I (sum < 23): possible odd sums are 15 (3, 5, 7), 19 (3, 5, 11) and 21 (3, 7, 11). Only 19 is prime, so the numbers are 3, 5, 11. Enough. Step 3: statement II (one number is 5): 3 + 5 + 11 = 19 and 5 + 7 + 11 = 23 both work. Not enough. So (a); options (b), (c) and (d) fail.
Tip: rule out the even prime 2 first in prime-sum questions; it changes odd/even results.
Answer as per the official UPSC answer key.
Read the passage
Not every voice on the internet commands the same kind of audience. When anonymous private entities with high capital can pay for more space for their opinions, they are effectively buying a louder voice. If political discourse in the digital sphere is a matter of outshining one’s opponent till the election is won, then the quality of politics suffers. The focus of social media is restricted to the promotion of content that generates more user engagement, regardless of how inflammatory the content may be.
Based on the above passage, the following assumptions have been made :
- 1. Internet is not inclusive enough.
- 2. Internet can adversely affect the quality of politics in a country.
Which of the assumptions given above is/are valid?
Answer (c) & explanation
Both assumptions are valid (c). Step 1: the passage opens: "Not every voice on the internet commands the same kind of audience." Rich players can buy a louder voice. So the internet is not equally open to all, that is, not inclusive enough (1). Step 2: it says that if online politics is just about outshining opponents, "the quality of politics suffers." So the internet can harm politics (2). Step 3: both ideas sit directly in the text, so options (a), (b) and (d) fail.
Tip: when a statement closely restates a line in the passage, it is valid. Underline key lines while reading. "Inclusive" means giving everyone a fair chance to be heard.
Answer as per the official UPSC answer key.
What is the sum of the first 28 terms in the following sequence?
1, 1, 2, 1, 3, 2, 1, 4, 3, 2, 1, 5, 4, 3, 2, …
Answer (b) & explanation
The sum of the first 28 terms is 84 (b). Step 1: group the terms: (1), (1, 2), (1, 3, 2), (1, 4, 3, 2), (1, 5, 4, 3, 2) … Group n has n terms and its sum is 1 + 2 + … + n. Step 2: 1 + 2 + … + 7 = 28 terms, so the first 28 terms are exactly groups 1 to 7. Step 3: sum = 1 + 3 + 6 + 10 + 15 + 21 + 28 = 84. Options (a), (c) and (d) are off by one.
Tip: odd-looking sequences often break into groups. Find where each group starts (here, every new 1) and the pattern becomes clear.
Answer as per the official UPSC answer key.
If in a certain code, 'POT' is written as ATOP and 'TRAP' is written as APART, then how is 'ARENA' written in that code?
Answer (d) & explanation
ARENA is written as AANERA (d). Step 1: look at the first example: POT reversed is TOP; adding A in front gives ATOP. Step 2: check the second: TRAP reversed is PART; with A in front: APART. So the rule is: reverse the word, then put A in front. Step 3: ARENA reversed is ANERA. With A in front: AANERA. Options (a), (b) and (c) do not follow the rule.
Tip: in coding questions, test your rule on every example before applying it. Reversal plus a fixed added letter is a common pattern.
Answer as per the official UPSC answer key.
Two persons P and Q enter into a business. P puts ₹ 14,000 more than Q, but P has invested for 8 months and Q has invested for 10 months. If P’s share is ₹ 400 more than Q’s share out of the total profit of ₹ 2,000, what is the capital contributed by P?
Answer (a) & explanation
P contributed ₹30,000 (a). Step 1: profit shares: P + Q = 2,000 and P − Q = 400. So P gets 1,200 and Q gets 800, a ratio of 3 : 2. Step 2: profit is shared by capital × months: 8p : 10q = 3 : 2. So 16p = 30q, and p : q = 15 : 8. Step 3: the gap of 7 parts is ₹14,000, so one part = ₹2,000 and P's capital = 15 × 2,000 = ₹30,000 (Q's is ₹16,000; check: 30,000 − 16,000 = 14,000). Options (b), (c) and (d) fail the check.
Tip: in partnership questions, profit ratio = capital × time. Always check your answer against every given fact.
Answer as per the official UPSC answer key.
A person walks 100 m Westward, then turns left and walks 100 m. He then takes 225° turn clockwise. In which direction is he walking now?
Answer (d) & explanation
He is now walking North-East (d). Step 1: he walks West. A left turn while facing West points South. Step 2: now turn 225° clockwise from South: 90° brings him to West, 180° to North, and 45° more (total 225°) to North-East. Step 3: so he faces North-East. Options (a), (b) and (c) come from turning the wrong way or miscounting the angle.
Tip: break big turns into 90° steps plus a remainder. Clockwise goes N → E → S → W; anticlockwise goes N → W → S → E. A 45° step lands on the corner directions (NE, SE, SW, NW).
the distances walked do not matter; only the facing direction does.
Answer as per the official UPSC answer key.
Read the passage
As inflation rises, even governments previously committed to budget discipline are spending freely to help households. Higher interest rates announced by central banks are supposed to help produce modest fiscal austerity, because to maintain stable debts while paying more to borrow, governments must cut spending or raise taxes. Without the fiscal backup, monetary policy eventually loses traction. Higher interest rates become inflationary, not disinflationary, because they simply lead governments to borrow more to pay rising debt-service costs. The risk of monetary unmooring is greater when public debt rises, because interest rates become more important to budget deficits.
Based on the above passage, the following assumptions have been made :
- 1. Fiscal policies of governments are solely responsible for higher prices.
- 2. Higher prices do not affect the long-term government bonds.
Which of the assumptions given above is/are valid?
Answer (d) & explanation
Neither assumption is valid (d). Step 1: assumption 1 says fiscal policies are "solely" responsible for higher prices. The passage only says government spending can weaken the central bank's fight against inflation. It never says spending is the only cause; supply shocks, for example, are not ruled out. Step 2: assumption 2 talks about long-term government bonds. The passage mentions debt-service costs, but says nothing about how prices affect long-term bonds. Step 3: neither idea is needed for the argument to work. So options (a), (b) and (c) fail.
Tip: reject any assumption with "solely" unless the passage clearly names one single cause. Also reject statements about things the passage never discusses, however sensible they sound.
Answer as per the official UPSC answer key.
Consider the following :
Weight of 6 boys = Weight of 7 girls = Weight of 3 men = Weight of 4 women
If the average weight of the women is 63 kg, then what is the average weight of the boys?
Answer (b) & explanation
The average weight of the boys is 42 kg (b). Step 1: the average weight of women is 63 kg, so 4 women weigh 4 × 63 = 252 kg. Step 2: 6 boys weigh the same as 4 women: 252 kg. Step 3: one boy, on average, weighs 252 ÷ 6 = 42 kg. The girls and men are extra information and can be ignored. Option (d), 63 kg, just repeats the women's figure. Options (a) and (c) are wrong.
Tip: CSAT often adds data you do not need. Find the shortest link between what is given and what is asked; here women to boys directly.
Answer as per the official UPSC answer key.
A Question is given followed by two Statements I and II. Consider the Question and the Statements.
Question : Is (x + y) an integer?
Statement-I : (2x + y) is an integer.
Statement-II : (x + 2y) is an integer.
Which one of the following is correct in respect of the above Question and the Statements?
Answer (d) & explanation
Even both statements together are not enough (d). Step 1: adding them: (2x + y) + (x + 2y) = 3(x + y) is an integer. So x + y is an integer divided by 3, which may or may not be whole. Step 2: test x = y = 1/3: 2x + y = 1 and x + 2y = 1 (integers), but x + y = 2/3, not an integer. Step 3: test x = y = 1: both statements hold and x + y = 2, an integer. Two different answers, so the question cannot be settled. Options (a), (b) and (c) fail.
Tip: in data sufficiency, try fractions. Many traps assume x and y must be whole numbers when the question never says so.
adding the two statements looks like it settles it. Always test a fraction before you accept "integer" claims.
Answer as per the official UPSC answer key.
222333 + 333222 is divisible by which of the following numbers?
Answer (b) & explanation
The sum is divisible by 3 and 37 but not by 2 (b). Step 1: break the bases: 222 = 6 × 37 and 333 = 9 × 37. Both are multiples of 3 and 37, so both terms, and their sum, are divisible by 3 and 37. Step 2: check 2: 222 is even, so 222^333 is even. 333 is odd, so 333^222 is odd. Step 3: even + odd = odd, so the sum is not divisible by 2. Options (a), (c) and (d) wrongly include 2 or exclude 37 or 3.
Tip: for divisibility of a sum, check each term. Even + odd is always odd. Spotting a common factor (here 111 = 3 × 37) saves big calculations.
Answer as per the official UPSC answer key.
A person buys three articles P, Q and R for ₹ 3,330. If P costs 25% more than R and R costs 20% more than Q, then what is the cost of P?
Answer (d) & explanation
P costs ₹1,350 (d). Step 1: start with the smallest item. Let Q = 100. R is 20% more: 120. P is 25% more than R: 120 + 30 = 150. Total = 370 parts. Step 2: 370 parts = ₹3,330, so one part = ₹9. Step 3: P = 150 × 9 = ₹1,350 (R = ₹1,080, Q = ₹900; total ₹3,330). Options (a), (b) and (c) do not fit the total.
Tip: take 100 for the item everything else is based on. Then convert parts to rupees in one step. Check with the total.
Answer as per the official UPSC answer key.
What will come in place of * in the sequence 3, 14, 39, 84, *, 258?
Answer (b) & explanation
The missing number is 155 (b). Step 1: take the differences: 14 − 3 = 11, 39 − 14 = 25, 84 − 39 = 45. Step 2: take the differences again: 25 − 11 = 14, 45 − 25 = 20. These rise by 6, so the next ones are 26 and 32. Step 3: next first differences: 45 + 26 = 71, then 71 + 32 = 103. So * = 84 + 71 = 155, and 155 + 103 = 258 checks out. Options (a), (c) and (d) fail the check.
Tip: if the first differences show no pattern, take differences of differences. Always confirm with the last given term.
Answer as per the official UPSC answer key.
P’s salary is 20% lower than Q’s salary which is 20% lower than R’s salary. By how much percent is R’s salary more than P’s salary?
Answer (b) & explanation
R's salary is 56.25% more than P's (b). Step 1: let R = 100. Q is 20% lower: 80. P is 20% lower than Q: 80 − 16 = 64. Step 2: R is more than P by 100 − 64 = 36. Step 3: "more than P" means the base is P: 36/64 × 100 = 56.25%. Option (a) and the others use the wrong base or add the two 20% cuts as 40%. Two 20% cuts do not make 40%.
Tip: "X is how much more than Y" always divides by Y. Taking 100 for the top value makes chained percentages easy. Two successive cuts of 20% give a total cut of 36%, not 40%.
"more than P's salary" means divide by P, not by R.
Answer as per the official UPSC answer key.
A Statement is given followed by two Conclusions numbered I and II. Consider the Statement and the Conclusions.
Statement : India is the world's largest producer of milk.
Conclusion-I : India is the world's largest exporter of milk.
Conclusion-II : India does not import milk.
Which one of the following is correct?
Answer (d) & explanation
Neither conclusion follows (d). Step 1: the statement only says India produces the most milk. Step 2: conclusion 1, largest exporter, does not follow. A country can be the biggest producer and also the biggest consumer, exporting very little. That is actually India's case. Step 3: conclusion 2, India does not import milk, does not follow either. A big producer may still import some milk products. Production says nothing about trade either way. So options (a), (b) and (c) fail.
Tip: producing, consuming, exporting and importing are four different things; do not jump from one to another. India has been the world's top milk producer since 1998, thanks to the White Revolution (Operation Flood).
don't bring in outside facts; judge only from the statement.
Answer as per the official UPSC answer key.
What is the least possible number of cuts required to cut a cube into 64 identical pieces?
Answer (b) & explanation
The least number of cuts is 9 (b). Step 1: 64 identical small cubes means 64 = 4 × 4 × 4. So each of the three directions (length, breadth, height) must be split into 4 parts. Step 2: to split one direction into 4 parts you need 3 cuts, since cuts are always one less than pieces. Step 3: three directions × 3 cuts = 3 + 3 + 3 = 9 cuts. Option (a), 8, is too few. Options (c), 12, and (d), 16, waste cuts.
Tip: for n × n × n identical pieces, the least cuts are 3(n − 1). For 27 pieces: 3 × 2 = 6 cuts. If the cuts are not equal in each direction, use (a − 1) + (b − 1) + (c − 1).
8 cuts can make at most 4 × 4 × 3 = 48 pieces, so 8 is not enough.
Answer as per the official UPSC answer key.
How many times the hour hand and the minute hand coincide in a clock between 10:00 a.m. and 2:00 p.m. (same day)?
Answer (a) & explanation
The hands coincide 3 times (a). Step 1: the hands meet every 12/11 hours, about 1 hour 5 minutes. In 12 hours they meet only 11 times, because between 11 and 1 they meet just once, at 12:00. Step 2: after 10:00 a.m., they meet at about 10:54, then at 12:00, then at about 1:05. Step 3: the next meeting is about 2:11, after the window. So 3 times. Option (b), 4, wrongly assumes once every hour.
Tip: hands meet 11 times in 12 hours and 22 times in a day. The 11-to-1 gap holds only one meeting, at 12 o'clock.
four hours does not mean four meetings. The 11 to 1 stretch has only one.
Traps like this come back in new clothes. The PYQ Book collects all of them, topic by topic, so none catch you twice. Try the free sample
Answer as per the official UPSC answer key.
A Question is given followed by two Statements I and II. Consider the Question and the Statements.
A person buys three articles p, q and r for ₹ 50. The price of the article q is ₹ 16 which is the least.
Question : What is the price of the article p?
Statement-I : The cost of p is not more than that of r.
Statement-II : The cost of r is not more than that of p.
Which one of the following is correct in respect of the above Question and the Statements?
Answer (c) & explanation
Both statements together are needed (c). Step 1: p + q + r = 50 and q = 16, so p + r = 34. Step 2: statement I says p ≤ r, so p could be 17 or less. Statement II says r ≤ p, so p could be 17 or more. Each alone leaves many values. Step 3: together, p ≤ r and r ≤ p force p = r = 17. A single answer. (q = 16 is still the least, as stated.) Options (a), (b) and (d) fail.
Tip: "not more than" (≤) and "not less than" (≥) together mean "equal to". Look for two statements that squeeze a value from both sides.
Answer as per the official UPSC answer key.