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.
If the order of the letters in the English alphabet is reversed and each letter represents the letter whose position it occupies, then which one of the following represents 'LUCKNOW'?
Answer (d) & explanation
LUCKNOW becomes OFXPMLD (d). Step 1: in the reversed alphabet, A ↔ Z, B ↔ Y, and so on. A letter at place n becomes the letter at place 27 − n. Step 2: L (12) → O (15); U (21) → F (6); C (3) → X (24); K (11) → P (16). Step 3: N (14) → M (13); O (15) → L (12); W (23) → D (4). So the code is OFXPMLD. Option (c) ends in E and options (a), (b) start O-G; each has one wrong letter.
Tip: remember pairs that add to 27 (like EJOTY at 5, 10, 15, 20, 25). Check only the letters where options differ.
Answer as per the official UPSC answer key.
Six persons A, B, C, D, E and F are sitting equidistant from each other around a circular table (facing the centre of the table).
Consider the Question and two Statements given below :
Question : Who is sitting on the immediate left of A?
Statement-1 : B is sitting opposite to C and D is sitting opposite to E.
Statement-2 : F is sitting on the immediate left of B.
Which one of the following is correct in respect of the Question and the Statements?
Answer (d) & explanation
Even both statements are not enough (d). Step 1: Statement-1 says B faces C and D faces E. With six seats, A must face F. Step 2: Statement-2 says F is on B's immediate left. This fixes B and F side by side, and C ends up on A's right. Step 3: A's immediate left is then a seat held by D or E, and D and E can swap. So it cannot be fixed. Options (a), (b) and (c) fail.
Tip: in circular seating, check if any two people can swap without breaking a rule. If yes, the answer is not fixed.
Answer as per the official UPSC answer key.
The average weight of A, B, C is 40 kg, the average weight of B, D, E is 42 kg and the weight of F is equal to that of B. What is the average weight of A, B, C, D, E and F?
Answer (c) & explanation
The average weight is 41 kg (c). Step 1: A + B + C = 3 × 40 = 120. B + D + E = 3 × 42 = 126. Step 2: adding them gives A + 2B + C + D + E = 246. Since F = B, this is just A + B + C + D + E + F = 246. Step 3: average = 246 ÷ 6 = 41 kg. Option (d) is wrong: F = B fills the gap. Options (a) and (b) are miscalculations.
Tip: when a person is counted twice, look for a clue that replaces the double count (here F = B).
it looks as if B is needed, but F = B makes it cancel out.
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Answer as per the official UPSC answer key.
A, B and C are three places such that there are three different roads from A to B, four different roads from B to C and three different roads from A to C. In how many different ways can one travel from A to C using these roads?
Answer (c) & explanation
There are 15 ways (c). Step 1: going A to B and then B to C: 3 × 4 = 12 ways. For "and then", multiply. Step 2: going directly from A to C: 3 ways. Step 3: the two routes are alternatives, so add: 12 + 3 = 15. Option (a), 10, adds all the numbers. Option (b), 13, misses some routes. Option (d), 36, multiplies everything.
Tip: "and" (one step after another) means multiply; "or" (choose one route) means add.
Answer as per the official UPSC answer key.
Consider the following statements in respect of a rectangular sheet of length 20 cm and breadth 8 cm :
- 1. It is possible to cut the sheet exactly into 4 square sheets.
- 2. It is possible to cut the sheet into 10 triangular sheets of equal area.
Which of the above statements is/are correct?
Answer (c) & explanation
Both statements are correct (c). Step 1: the squares need not be equal. Cut two 8 × 8 squares from the 20 × 8 sheet. The leftover 4 × 8 strip makes two 4 × 4 squares. That is exactly 4 squares (1 is true). Step 2: cut the sheet into five 4 × 8 rectangles. Cut each along a diagonal to get two equal triangles. That gives 10 triangles of equal area (2 is true). Step 3: so options (a), (b) and (d) fail.
Tip: read "exactly 4 square sheets" carefully: it does not say equal squares. Don't add conditions the question does not state.
nothing says the four squares must be equal.
Answer as per the official UPSC answer key.
Two friends X and Y start running and they run together for 50 m in the same direction and reach a point. X turns right and runs 60 m, while Y turns left and runs 40 m. Then X turns left and runs 50 m and stops, while Y turns right and runs 50 m and then stops. How far are the two friends from each other now?
Answer (a) & explanation
They are 100 m apart (a). Step 1: say they first run 50 m North together. Step 2: X turns right (East) and runs 60 m. Y turns left (West) and runs 40 m. Now they are 60 + 40 = 100 m apart on an east-west line. Step 3: X turns left (North) and runs 50 m. Y turns right (also North) and runs 50 m. Both move the same distance in the same direction, so the gap stays 100 m. Options (b), (c) and (d) miss this.
Tip: draw a quick sketch. When two people move the same distance in the same direction, the distance between them does not change.
the first 50 m and the last 50 m are common to both, so ignore them.
Answer as per the official UPSC answer key.
Two Statements followed by four Conclusions are 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 the Conclusions and then decide which of the given Conclusions logically follows/follow from the Statements, disregarding the commonly known facts :
Statement-1 : All pens are books.
Statement-2 : No chair is a pen.
Conclusion-I : All chairs are books.
Conclusion-II : Some chairs are pens.
Conclusion-III : All books are chairs.
Conclusion-IV : No chair is a book.
Which one of the following is correct?
Answer (d) & explanation
None of the conclusions follows (d). Step 1: draw pens inside books, and chairs outside pens. Step 2: chairs may overlap the part of books that is not pens, or may lie fully outside books. So "all chairs are books" (I) and "no chair is a book" (IV) are both only possible, not certain. Step 3: "some chairs are pens" (II) contradicts Statement-2. "All books are chairs" (III) cannot be true because pens are books but not chairs. So options (a), (b) and (c) fail.
Tip: draw the circles in more than one way. A conclusion follows only if it holds in every drawing.
'No chair is a pen' does not mean 'no chair is a book'. Books are bigger than pens.
Answer as per the official UPSC answer key.
A pie chart gives the expenditure on five different items A, B, C, D and E in a household. If B, C, D and E correspond to 90°, 50°, 45° and 75° respectively, then what is the percentage of expenditure on item A?
Answer (d) & explanation
Item A is 250/9 % (d). Step 1: a full pie is 360°. B + C + D + E = 90 + 50 + 45 + 75 = 260°. Step 2: so A gets 360 − 260 = 100°. Step 3: as a percentage: 100 ÷ 360 × 100 = 10000 ÷ 360 = 250/9 (about 27.8%). Options (a), (b) and (c) use wrong angles.
Tip: in pie charts, 1% = 3.6° and 1° = 5/18 %. So 100° = 500/18 = 250/9 %.
Answer as per the official UPSC answer key.
In a tournament of Chess having 150 entrants, a player is eliminated whenever he loses a match. It is given that no match results in a tie/draw. How many matches are played in the entire tournament?
Answer (c) & explanation
149 matches are played (c). Step 1: every match has a loser, and every loser is knocked out. No match is drawn. Step 2: in the end only one champion is left. So 150 − 1 = 149 players must be knocked out. Step 3: one match per knocked-out player means 149 matches. Option (b), 150, counts the champion too. Options (a) and (d) are off by one in other ways.
Tip: in any knockout tournament with n players, the number of matches is n − 1, whatever the number of rounds or byes.
Answer as per the official UPSC answer key.
Consider the Question and two Statements given below :
Question: What is the age of Manisha?
Statement-1 : Manisha is 24 years younger than her mother.
Statement-2 : 5 years later, the ages of Manisha and her mother will be in the ratio 3 : 5.
Which one of the following is correct in respect of the Question and the Statements?
Answer (c) & explanation
Both statements together are sufficient (c). Step 1: Statement-1 alone says Manisha is 24 years younger than her mother. That is one link between two unknowns, so it is not enough. Step 2: Statement-2 alone gives a future ratio, again with two unknowns. Not enough. Step 3: together: if Manisha is m, her mother is m + 24. In 5 years: (m + 5) ÷ (m + 29) = 3 ÷ 5. So 5m + 25 = 3m + 87, and m = 31. Options (a), (b) and (d) fail.
Tip: two unknowns need two independent facts. Each statement here gives one, so together they suffice.
Answer as per the official UPSC answer key.
A has some coins. He gives half of the coins and 2 more to B. B gives half of the coins and 2 more to C. C gives half of the coins and 2 more to D. The number of coins D has now, is the smallest two-digit number. How many coins does A have in the beginning?
Answer (d) & explanation
A had 52 coins at the start (d). Step 1: the smallest two-digit number is 10, so D has 10. Work backwards. Step 2: D got half of C's coins plus 2. So half of C's coins = 8, and C had 16. Step 3: C got half of B's plus 2, so half of B's = 14 and B had 28. B got half of A's plus 2, so half of A's = 26 and A had 52. Options (a), (b) and (c) fail this check.
Tip: when a chain of "half plus 2" ends at a known number, reverse each step: subtract 2, then double.
Answer as per the official UPSC answer key.
When 70% of a number x is added to another number y, the sum becomes 165% of the value of y. When 60% of the number x is added to another number z, then the sum becomes 165% of the value of z. Which one of the following is correct?
Answer (a) & explanation
The order is z < x < y (a). Step 1: 70% of x + y = 165% of y. So 70% of x = 65% of y. A bigger share of x equals a smaller share of y, so y is bigger than x. Step 2: 60% of x + z = 165% of z. So 60% of x = 65% of z. A bigger share of z equals a smaller share of x, so z is smaller than x. Step 3: together: z < x < y. Options (b), (c) and (d) get the order wrong.
Tip: if a% of P = b% of Q and a is larger than b, then P is smaller than Q. The number taking the bigger percentage is the smaller one.
Answer as per the official UPSC answer key.
Which date of June 2099 among the following is Sunday?
Answer (d) & explanation
1. Use a known day as an anchor: 1 January 2001 was a Monday. From 1 Jan 2001 to 1 Jan 2099 is 98 years, with 24 leap years (2004 to 2096). Odd days = 98 + 24 = 122, which leaves 3 on division by 7. So 1 January 2099 is Thursday.
2. January to May 2099 (not a leap year) = 31 + 28 + 31 + 30 + 31 = 151 days, which leaves 4. So 1 June 2099 is Thursday + 4 = Monday.
3. 1 June is Monday, so 7 June is Sunday.
Answer as per the official UPSC answer key.
Three Statements followed by three Conclusions are 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 the Conclusions and then decide which of the given Conclusions logically follows/follow from the Statements, disregarding the commonly known facts :
Statement-1 : Some doctors are teachers.
Statement-2 : All teachers are engineers.
Statement-3 : All engineers are scientists.
Conclusion-I : Some scientists are doctors.
Conclusion-II : All engineers are doctors.
Conclusion-III : Some engineers are doctors.
Which one of the following is correct?
Answer (c) & explanation
Conclusions I and III follow (c). Step 1: some doctors are teachers. All teachers are engineers, so those doctors are also engineers. Step 2: all engineers are scientists, so those doctors are also scientists. So "some engineers are doctors" (III) and "some scientists are doctors" (I) follow. Step 3: "all engineers are doctors" (II) does not follow; only some are. So options (a), (b) and (d) fail.
Tip: follow the small "some" group through each "all" statement. Wherever it goes, a "some" conclusion follows.
Answer as per the official UPSC answer key.
Read the passage
To encourage research is one of the functions of a university. Contemporary universities have encouraged research, not only in those cases where research is necessary, but on all sorts of entirely unprofitable subjects as well. Scientific research is probably never completely valueless. However silly and insignificant it may seem, however mechanical and unintelligent the labours of the researchers, there is always a chance that the results may be of value to the investigator of talent, who can use the facts collected for him by uninspired but industrious researchers as the basis of some fruitful generalization. But where research is not original, but consists in the mere rearrangement of existing materials, where its object is not scientific but literary or historical, then there is a risk of the whole business becoming merely futile.
The author’s assumption about scientific research is that
Answer (c) & explanation
The author assumes scientific research is never without some value (c). Step 1: the passage says scientific research is "probably never completely valueless". That means it always has some value. That is (c). Step 2: option (d) says it is always very valuable, which inflates "some value". Step 3: option (a), never very valuable, and option (b), sometimes very valuable, are not what the author says.
Tip: "never completely valueless" = "always has some value". Keep the strength of the claim exactly as the passage puts it.
Answer as per the official UPSC answer key.
How many 3-digit natural numbers (without repetition of digits) are there such that each digit is odd and the number is divisible by 5 ?
Answer (b) & explanation
There are 12 such numbers (b). Step 1: a number divisible by 5 ends in 0 or 5. Since every digit must be odd, the last digit must be 5. Step 2: the first two digits come from the other odd digits: 1, 3, 7, 9. No repeats allowed. Step 3: the first digit has 4 choices and the second has 3. So 4 × 3 = 12. Option (a), 8, and the larger options (c) 16 and (d) 24 miscount.
Tip: fill the most restricted place first (here, the last digit). Then count the choices for the rest.
Answer as per the official UPSC answer key.
Six lectures A, B, C, D, E and F, each of one hour duration, are scheduled between 8:00 a.m. and 2:00 p.m.
Consider the Question and two Statements given below :
Question : Which lecture is in the third period?
Statement-1 : Lecture F is preceded by A and followed by C.
Statement-2 : There is no lecture after lecture B.
Which one of the following is correct in respect of the Question and the Statements?
Answer (d) & explanation
Even both statements are not enough (d). Step 1: Statement-2 says no lecture comes after B, so B is in the 6th period. Step 2: Statement-1 says A, F and C come one after another as a block A–F–C. This block sits somewhere in periods 1 to 5, along with D and E. Step 3: the block can start in period 1, 2 or 3. So the third period could hold C, F or A. It cannot be fixed. Options (a), (b) and (c) fail.
Tip: "preceded by A and followed by C" makes a fixed block. Count how many places the block can slide into.
Answer as per the official UPSC answer key.
In the series AABABCABCDABCDE..., which letter appears at the 100th place?
Answer (c) & explanation
The 100th letter is I (c). Step 1: the series is in groups: A, AB, ABC, ABCD and so on. Group n has n letters. Step 2: the first 13 groups fill 1 + 2 + ... + 13 = 13 × 14 ÷ 2 = 91 places. Step 3: group 14 starts at place 92. Place 100 is the 9th letter of that group, which is I. Options (a) G, (b) H and (d) J are one or two places off.
Tip: the sum of the first n numbers is n(n + 1)/2. It quickly tells you which group a position falls in.
Answer as per the official UPSC answer key.
Read the passage
The majority of people who fail to accumulate money sufficient for their needs, are generally, easily influenced by the opinions of others. They permit the newspapers and the gossiping neighbours to do their thinking for them. Opinions are the cheapest commodities on the earth. Everyone has a flock of opinions ready to be wished upon by anyone who will accept them. If you are influenced by opinions when you reach decisions, you will not succeed in any undertaking.
Which one of the following is implied by the passage?
Answer (c) & explanation
The passage implies there are people who fail to save enough money for their needs (c). Step 1: it begins: "The majority of people who fail to accumulate money..." This assumes such people exist. That is (c). Step 2: option (a) says most people do not save. But the passage speaks of the majority of those who fail, not most people overall. Step 3: option (b) says most people never fail, which the passage does not say. Option (d), no need to save, goes against it.
Tip: an implication can hide in the subject of a sentence. "The majority of X" quietly assumes X exists.
Answer as per the official UPSC answer key.
A bill for ₹ 1,840 is paid in the denominations of ₹ 50, ₹ 20 and ₹ 10 notes. 50 notes in all are used. Consider the following statements :
- 1. 25 notes of ₹ 50 are used and the remaining are in the denominations of ₹ 20 and ₹ 10.
- 2. 35 notes of ₹ 20 are used and the remaining are in the denominations of ₹ 50 and ₹ 10.
- 3. 20 notes of ₹ 10 are used and the remaining are in the denominations of ₹ 50 and ₹ 20.
Which of the above statements are not correct?
Answer (d) & explanation
1. a + b + c = 50 and 50a + 20b + 10c = 1840. Subtract 10 × the first: 4a + b = 134.
2. 1: a = 25 gives b = 34, but then c = –9. Impossible. 2: b = 35 needs 4a = 99. Not a whole number.
3. 3: c = 20 gives a + b = 30 and 4a + b = 134, so a = 34·67. Impossible. All three are not correct.
the question asks which are not correct.
Answer as per the official UPSC answer key.