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CSAT · 113 questions

Puzzles, arrangements & general mental ability

Every UPSC CSAT question on this topic, 2016–2026, newest first. Tap an option to check yourself; the answer and explanation open below it.

Puzzles, arrangements & general mental ability questions per year: 2016: 19, 2017: 18, 2018: 17, 2019: 10, 2020: 3, 2021: 10, 2022: 5, 2023: 7, 2024: 8, 2025: 8, 2026: 8 Asked in 11 of 11 years · most in 2016 (19)

UPSC syllabus: “General mental ability;” See the full syllabus →

Showing 91–113 of 113, newest first.

CSAT 2017 · Q72

Easy

In a school, there are five teachers A, B, C, D and E. A and B teach Hindi and English. C and B teach English and Geography. D and A teach Mathematics and Hindi. E and B teach History and French. Who teaches maximum number of subjects?

Answer & explanation

Answer: (b) B

Collect each teacher's subjects, counting a repeated subject once. B teaches Hindi, English, Geography, History and French — five subjects. A teaches three, and C, D and E teach two each.

  1. A: Hindi, English (with B) and Mathematics, Hindi (with D) → Hindi, English, Mathematics = 3.
  2. B: Hindi, English; English, Geography; History, French → Hindi, English, Geography, History, French = 5.
  3. C: English, Geography = 2. D: Mathematics, Hindi = 2. E: History, French = 2.
  4. B teaches the most subjects.

Remember · List each person's subjects as a set, counting a subject once even if it appears in two statements.

Question and answer: UPSC's official GS Paper II (2017, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

CSAT 2017 · Q76

Medium

Directions for the following 3 (three) items: Consider the given information and answer the three items that follow.

Eight railway stations A, B, C, D, E, F, G and H are connected either by two-way passages or one-way passages. One-way passages are from C to A, E to G, B to F, D to H, G to C, E to C and H to G. Two-way passages are between A and E, G and B, F and D, and E and D.

While travelling from C to H, which one of the following stations must be passed through?

Answer & explanation

Answer: (b) E

UPSC's official answer: (b) · the answer UPSC accepted, and the one that counts in the exam

Also defensible: (c)

  • Exits from each station: A → E; B → F, G; C → A; D → H, F, E; E → G, C, A, D; F → D; G → C, B; H → G.
  • Working forward: C's only exit is A, and A's only exit is E, so every route from C passes through E. That is UPSC's (b).
  • Working backward: the only passage into H is D → H, so every route must also pass through D. The two complete routes are C → A → E → D → H and C → A → E → G → B → F → D → H; both contain E and D.
  • G and F lie only on the longer route, so (a) and (d) are wrong; but (b) and (c) are both forced, and the item has two correct options.

UPSC's key is (b) E, which every route must pass through; D is equally unavoidable, so (c) is also correct. In the exam, trace the forced moves from the start station first, as the key does, and give E.

This box is Minimalist IAS's analysis, with its sources; it does not change UPSC's answer.

From C the only exit is to A, and from A the only onward move is to E, so every journey from C to H has to pass through E. G and F lie only on the longer of the two routes, so they are not compulsory.

  1. Exits from each station: A → E; B → F, G; C → A; D → H, F, E; E → G, C, A, D; F → D; G → C, B; H → G.
  2. From C the only move is to A, and from A the only move is to E — so E is on every route out of C.
  3. Routes to H: C → A → E → D → H, or C → A → E → G → B → F → D → H; both pass through E.
  4. G and F appear only on the longer route, so they are not compulsory; E is the station UPSC's key accepts.

Remember · For 'must pass through', trace the forced moves from the start: a station with a single exit forces the next station onto every route.

Question and answer: UPSC's official GS Paper II (2017, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 1 Oct 2026 (how we verify). Permalink ·

CSAT 2017 · Q77

Medium

Directions for the following 3 (three) items: Consider the given information and answer the three items that follow.

Eight railway stations A, B, C, D, E, F, G and H are connected either by two-way passages or one-way passages. One-way passages are from C to A, E to G, B to F, D to H, G to C, E to C and H to G. Two-way passages are between A and E, G and B, F and D, and E and D.

In how many different ways can a train travel from F to A without passing through any station more than once?

Answer & explanation

Answer: (d) 4

From F the only exit is D, and from D the train can go to E or H. Through E it reaches A directly, via C, or via G and C (3 routes); through H it must go to G, then C, then A (1 route). That makes 4 routes.

  1. Exits from each station: A → E; B → F, G; C → A; D → H, F, E; E → G, C, A, D; F → D; G → C, B; H → G.
  2. F's only exit is D.
  3. D → E: then E → A (F-D-E-A), E → C → A (F-D-E-C-A), or E → G → C → A (F-D-E-G-C-A). E → G → B leads only back to F or G, already used.
  4. D → H: H → G, then G → C → A (F-D-H-G-C-A); G → B leads back to F — a dead end.
  5. Total routes without repeating a station = 3 + 1 = 4.

Remember · Count routes with a tree: branch at every station and prune any branch that revisits a station or reaches a dead end.

Question and answer: UPSC's official GS Paper II (2017, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

CSAT 2017 · Q78

Medium

Directions for the following 3 (three) items: Consider the given information and answer the three items that follow.

Eight railway stations A, B, C, D, E, F, G and H are connected either by two-way passages or one-way passages. One-way passages are from C to A, E to G, B to F, D to H, G to C, E to C and H to G. Two-way passages are between A and E, G and B, F and D, and E and D.

If the route between G and C is closed, which one of the following stations need not be passed through while travelling from H to C?

Answer & explanation

Answer: (c) A

H's only exit is G, and with G to C closed, G must go to B, then F, then D. From D the train reaches C only through E. The route H-G-B-F-D-E-C passes E, D and B but never needs A.

  1. Exits from each station: A → E; B → F, G; C → A; D → H, F, E; E → G, C, A, D; F → D; G → C, B; H → G.
  2. H → G is the only exit from H.
  3. G → C is closed, so G → B; then B → F (B → G goes back) and F → D.
  4. From D: D → H goes back, so D → E; from E go straight to C.
  5. Route: H → G → B → F → D → E → C. It passes E, D and B but not A.
  6. A can be entered only from C or E and leads only back to E, so it is never needed.

Remember · When a link closes, trace the forced path one exit at a time; stations off that path need not be passed.

Question and answer: UPSC's official GS Paper II (2017, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

CSAT 2016 · Q9

Easy

A person X was driving in a place where all roads ran either north-south or east-west, forming a grid. Roads are at a distance of 1 km from each other in a parallel. He started at the intersection of two roads, drove 3 km north, 3 km west and 4 km south. Which further route could bring him back to his starting point, if the same route is not repeated?

Answer & explanation

Answer: (b) 3 km east, then 1 km north

After 3 km north, 3 km west and 4 km south he is 3 km west and 1 km south of the start. Driving 3 km east and then 1 km north brings him back without retracing any stretch.

  1. Take the start as (0, 0), with east and north positive.
  2. 3 km north → (0, 3); 3 km west → (−3, 3); 4 km south → (−3, −1).
  3. To return he must go 3 km east and 1 km north.
  4. (b): 3 km east → (0, −1), then 1 km north → (0, 0). Neither stretch repeats an earlier one.
  5. Check: (a) ends at (0, −3), (c) at (−5, 0), (d) at (−3, −3).

Remember · Track direction problems as coordinates: add north and east, subtract south and west, then read off the move back to (0, 0).

Question and answer: UPSC's official GS Paper II (2016, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

CSAT 2016 · Q12

Medium

Five people A, B, C, D and E are seated about a round table. Every chair is spaced equidistant from adjacent chairs.

(i) C is seated next to A

(ii) A is seated two seats from D

(iii) B is not seated next to A

On the basis of above information, which of the following must be true?

  1. 1.D is seated next to B
  2. 2.E is seated next to A
  3. 3.D and C are separated by two seats

Select the correct answer using the code given below:

Answer & explanation

Answer: (b) 1 and 2 only

A's two neighbours can only be C and E, because D is two seats away and B is not next to A. B and D then fill the two adjacent seats away from A, so D is always beside B. D may sit beside C or beside E, so statement 3 is not certain.

  1. With 5 seats in a circle, each person has exactly two neighbours.
  2. A's neighbours: C (i); not D, who is two seats away (ii); not B (iii). So the other neighbour is E — statement 2 must be true.
  3. The two remaining seats are next to each other and each is two seats from A; B and D take them in either order.
  4. So D always sits next to B — statement 1 must be true.
  5. If D takes the seat beside C, D and C are adjacent; so statement 3 need not be true.
  • ✓ 1. B and D fill the two adjacent seats not next to A.
  • ✓ 2. A's only possible neighbours are C and E.
  • ✗ 3. In one valid arrangement D sits right beside C, so this is not certain.

Remember · In small circular seatings, fix one person, settle the neighbours first, and treat 'must be true' as true in every valid arrangement.

Question and answer: UPSC's official GS Paper II (2016, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

CSAT 2016 · Q15

Easy

Directions for the following 5 (five) items: Consider the following information and answer the five items that follow:

There are five persons in a group — P, Q, R, S and T. The group has one doctor, one lawyer and one artist. P and S are unmarried students. T is a man married to one of the group members. Q is the brother of P and is neither doctor nor artist. R is not doctor.

Who is the doctor?

Answer & explanation

Answer: (a) T

P and S are students, so the three professions belong to Q, R and T. Q is the lawyer (neither doctor nor artist) and R is not the doctor, so the doctor is T.

  1. P and S are students, so the doctor, lawyer and artist are among Q, R and T.
  2. Q is neither doctor nor artist, so Q is the lawyer.
  3. R is not the doctor, so R is the artist and T is the doctor.

Remember · Strike out people who can hold no role first, then fill roles from the most restricted person; one 'is not' often fixes two others.

Question and answer: UPSC's official GS Paper II (2016, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

CSAT 2016 · Q16

Easy

Directions for the following 5 (five) items: Consider the following information and answer the five items that follow:

There are five persons in a group — P, Q, R, S and T. The group has one doctor, one lawyer and one artist. P and S are unmarried students. T is a man married to one of the group members. Q is the brother of P and is neither doctor nor artist. R is not doctor.

Who is the artist?

Answer & explanation

Answer: (c) R

The professions belong to Q, R and T, since P and S are students. Q must be the lawyer, and R, who is not the doctor, must be the artist.

  1. P and S are students, so the doctor, lawyer and artist are among Q, R and T.
  2. Q is neither doctor nor artist, so Q is the lawyer.
  3. R is not the doctor, so R is the artist and T is the doctor.

Remember · Strike out people who can hold no role first, then fill roles from the most restricted person; one 'is not' often fixes two others.

Question and answer: UPSC's official GS Paper II (2016, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

CSAT 2016 · Q17

Easy

Directions for the following 5 (five) items: Consider the following information and answer the five items that follow:

There are five persons in a group — P, Q, R, S and T. The group has one doctor, one lawyer and one artist. P and S are unmarried students. T is a man married to one of the group members. Q is the brother of P and is neither doctor nor artist. R is not doctor.

Who is the spouse of R?

Answer & explanation

Answer: (b) T

T is married to a group member. P and S are unmarried, and Q (P's brother) is a man like T, so T's spouse can only be R.

  1. T is married to someone in the group.
  2. P and S are unmarried, so T's spouse is Q or R.
  3. Q is P's brother, a man; T is also a man. The puzzle treats marriage as between a man and a woman, so T's spouse is R.

Remember · In relation puzzles, list who is ruled out — unmarried, same family, same sex — and the spouse is whoever remains.

Question and answer: UPSC's official GS Paper II (2016, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

CSAT 2016 · Q18

Easy

Directions for the following 5 (five) items: Consider the following information and answer the five items that follow:

There are five persons in a group — P, Q, R, S and T. The group has one doctor, one lawyer and one artist. P and S are unmarried students. T is a man married to one of the group members. Q is the brother of P and is neither doctor nor artist. R is not doctor.

Who is the lawyer?

Answer & explanation

Answer: (b) Q

P and S are students, so only Q, R and T hold the professions. Q is neither doctor nor artist, so Q is the lawyer.

  1. P and S are students, so the doctor, lawyer and artist are among Q, R and T.
  2. Q is neither doctor nor artist, so Q is the lawyer.

Remember · Strike out people who can hold no role first, then fill roles from the most restricted person; one 'is not' often fixes two others.

Question and answer: UPSC's official GS Paper II (2016, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

CSAT 2016 · Q19

Easy

Directions for the following 5 (five) items: Consider the following information and answer the five items that follow:

There are five persons in a group — P, Q, R, S and T. The group has one doctor, one lawyer and one artist. P and S are unmarried students. T is a man married to one of the group members. Q is the brother of P and is neither doctor nor artist. R is not doctor.

Who of the following is definitely a man?

Answer & explanation

Answer: (c) Q

Q is described as the brother of P, so Q is certainly a man. Nothing fixes the sex of P or S. T is also a man, but T is not among the options.

  1. Q is 'the brother of P' — so Q is a man.
  2. P and S are only called unmarried students; their sex is not given.
  3. T is 'a man' but is not an option, so the answer is Q.

Remember · 'Definitely' needs a direct word in the data — brother, man, husband; roles like student or doctor say nothing about sex.

Question and answer: UPSC's official GS Paper II (2016, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

CSAT 2016 · Q27

Medium

Four friends A, B, C and D need to cross a bridge. A maximum of two persons can cross it at a time. It is night and they just have one lamp. Persons that cross the bridge must carry the lamp to find the way. A pair must walk together at the speed of slower person. After crossing the bridge, the person having faster speed in the pair will return with the lamp each time to accompany another person in the group. Finally, the lamp has to be returned at the original place and the person who returns the lamp has to cross the bridge again without lamp. To cross the bridge, the time taken by them is as follows: A: 1 minute, B: 2 minutes, C: 7 minutes and D: 10 minutes. What is the total minimum time required by all the friends to cross the bridge?

Answer & explanation

Answer: (a) 23 minutes

Because the faster member of each pair must bring the lamp back, A (1 minute) should escort each of the others: 10 + 1 + 7 + 1 + 2 = 21 minutes. Taking the lamp back and crossing again without it adds A's 1 + 1 minutes, giving 23.

  1. The faster person of each pair returns with the lamp, so the fastest, A, should pair with each of the others.
  2. A and D cross: 10 min; A returns: 1 min.
  3. A and C cross: 7 min; A returns: 1 min.
  4. A and B cross: 2 min. All are across after 10 + 1 + 7 + 1 + 2 = 21 min.
  5. A takes the lamp back (1 min) and crosses again without it (1 min): 21 + 2 = 23 minutes.
  6. Check: any pair without A sends back B or slower, which only adds time.

Remember · Read the special rules first: here the faster partner must return, so the fastest person should shuttle everyone.

Question and answer: UPSC's official GS Paper II (2016, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

CSAT 2016 · Q34

Medium

Direction for the following 3 (three) items: Consider the given information and answer the three items that follow.

Six boxes A, B, C, D, E and F have been painted with six different colours viz., violet, indigo, blue, green, yellow and orange and arranged from left to right (not necessarily either kept or painted with the colours in the same order). Each box contains a ball of any one of the following six games: cricket, hockey, tennis, golf, football and volleyball (not necessarily in the same order). The golf ball is in violet box and is not in the box D. The box A which contains tennis ball is orange in colour and is at the extreme right. The hockey ball is neither in box D nor in box E. The box C having cricket ball is painted green. The hockey ball is neither in the box painted blue nor in the box painted yellow. The box C is fifth from right and next to box B. The box B contains volleyball. The box containing the hockey ball is between the boxes containing golf ball and volleyball.

Which one of the following boxes contains the golf ball?

Answer & explanation

Answer: (b) E

Hockey cannot be in A, B or C (their balls are known) or in D and E, so it is in F. Golf is not in D, so golf must be in E, leaving football for D.

  1. Stated outright: A — tennis, orange; C — cricket, green; B — volleyball.
  2. Hockey is not in D or E, and A, B, C already hold other balls, so hockey is in F.
  3. Golf is not in D, so golf is in E and football is left for D.

Remember · In box puzzles, fix what is stated outright, then place the item with the most 'not' clues; note what stays open before answering.

Question and answer: UPSC's official GS Paper II (2016, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

CSAT 2016 · Q35

Medium

Direction for the following 3 (three) items: Consider the given information and answer the three items that follow.

Six boxes A, B, C, D, E and F have been painted with six different colours viz., violet, indigo, blue, green, yellow and orange and arranged from left to right (not necessarily either kept or painted with the colours in the same order). Each box contains a ball of any one of the following six games: cricket, hockey, tennis, golf, football and volleyball (not necessarily in the same order). The golf ball is in violet box and is not in the box D. The box A which contains tennis ball is orange in colour and is at the extreme right. The hockey ball is neither in box D nor in box E. The box C having cricket ball is painted green. The hockey ball is neither in the box painted blue nor in the box painted yellow. The box C is fifth from right and next to box B. The box B contains volleyball. The box containing the hockey ball is between the boxes containing golf ball and volleyball.

Which of the following statements is/are correct?

Answer & explanation

Answer: (b) F is painted indigo

Hockey is in F, and F can be neither blue nor yellow; orange, green and violet belong to A, C and E, so F is indigo. B and D take blue and yellow in an order the clues never fix, so only (b) is certain.

  1. Stated outright: A — tennis, orange; C — cricket, green; B — volleyball.
  2. Hockey is not in D or E, and A, B, C already hold other balls, so hockey is in F.
  3. Golf is not in D, so golf is in E and football is left for D.
  4. Golf is in the violet box, so E is violet.
  5. F (hockey) is neither blue nor yellow; orange, green and violet are taken, so F is indigo.
  6. B and D share blue and yellow, and no clue says which is which.
  • ✗ (a) D may be blue or yellow — not fixed.
  • ✓ (b) F must be indigo.
  • ✗ (c) B may be blue or yellow — not fixed.
  • ✗ (d) Only (b) is certain.

Remember · In box puzzles, fix what is stated outright, then place the item with the most 'not' clues; note what stays open before answering.

Question and answer: UPSC's official GS Paper II (2016, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

CSAT 2016 · Q36

Medium

Direction for the following 3 (three) items: Consider the given information and answer the three items that follow.

Six boxes A, B, C, D, E and F have been painted with six different colours viz., violet, indigo, blue, green, yellow and orange and arranged from left to right (not necessarily either kept or painted with the colours in the same order). Each box contains a ball of any one of the following six games: cricket, hockey, tennis, golf, football and volleyball (not necessarily in the same order). The golf ball is in violet box and is not in the box D. The box A which contains tennis ball is orange in colour and is at the extreme right. The hockey ball is neither in box D nor in box E. The box C having cricket ball is painted green. The hockey ball is neither in the box painted blue nor in the box painted yellow. The box C is fifth from right and next to box B. The box B contains volleyball. The box containing the hockey ball is between the boxes containing golf ball and volleyball.

The football is in the box of which colour?

Answer & explanation

Answer: (c) Cannot be determined as data are inadequate

Football ends up in box D. But D and B share blue and yellow, and no clue decides which of them is which, so the colour of the football's box cannot be determined.

  1. Stated outright: A — tennis, orange; C — cricket, green; B — volleyball.
  2. Hockey is not in D or E, and A, B, C already hold other balls, so hockey is in F.
  3. Golf is not in D, so golf is in E and football is left for D.
  4. Golf is in the violet box, so E is violet.
  5. F (hockey) is neither blue nor yellow; orange, green and violet are taken, so F is indigo.
  6. B and D share blue and yellow, and no clue says which is which.

Remember · In box puzzles, fix what is stated outright, then place the item with the most 'not' clues; note what stays open before answering.

Question and answer: UPSC's official GS Paper II (2016, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

CSAT 2016 · Q38

Medium

A daily train is to be introduced between station A and station B starting from each end at 6 AM and the journey is to be completed in 42 hours. What is the number of trains needed in order to maintain the shuttle service?

Answer & explanation

Answer: (c) 4

A train leaving at 6 AM arrives 42 hours later, at midnight, and can start back only at the next 6 AM — so each one-way trip uses 2 days and a round trip 4 days. With a departure needed every day, 4 trains keep the shuttle going.

  1. Leaving A at 6 AM on day 1, a train reaches B 42 hours later — midnight at the end of day 2.
  2. It starts back from B at 6 AM on day 3 and reaches A at midnight at the end of day 4.
  3. It leaves A again at 6 AM on day 5: one full cycle takes 4 days.
  4. A train must leave A every day, so 4 trains are needed (trains 1–4 leave A on days 1–4; train 1 is back for day 5).
  5. Check: the same 4 trains also give a daily 6 AM departure from B, each leaving B two days after leaving A.

Remember · For a shuttle, find one train's full cycle, waiting included; trains needed = cycle in days × daily departures from one end.

Question and answer: UPSC's official GS Paper II (2016, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

CSAT 2016 · Q53

Easy

A person is standing on the first step from the bottom of a ladder. If he has to climb 4 more steps to reach exactly the middle step, how many steps does the ladder have?

Answer & explanation

Answer: (b) 9

Step 1 plus 4 more is step 5, the middle step. A middle step with 4 steps below it has 4 above it too, so the ladder has 9 steps.

  1. He stands on step 1; 4 more steps bring him to step 5.
  2. Step 5 is the middle, so there are 4 steps below it and 4 above it.
  3. Total = 4 + 1 + 4 = 9.

Remember · If the kth item is exactly the middle one, the total is 2k − 1.

Question and answer: UPSC's official GS Paper II (2016, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

CSAT 2016 · Q54

Medium

Direction for the following 3 (three) items: Consider the given information and answer the three items that follow.

When three friends A, B and C met, it was found that each of them wore an outer garment of a different colour. In random order, the garments are: jacket, sweater and tie; and the colours are: blue, white and black. Their surnames in random order are: Ribeiro, Kumar and Singh.

Further, we know that:

1. neither B nor Ribeiro wore a white sweater

2. C wore a tie

3. Singh's garment was not white

4. Kumar does not wear a jacket

5. Ribeiro does not like to wear the black colour

6. Each of the friends wore only one outer garment of only one colour

What is C's surname?

Answer & explanation

Answer: (a) Ribeiro

Only A can have worn the white sweater (B is excluded and C wore the tie), so A is Kumar. 'Neither B nor Ribeiro' shows B is not Ribeiro, so B is Singh and C is Ribeiro.

  1. Clue 1 speaks of a white sweater worn by someone other than B and Ribeiro; it also tells us B is not Ribeiro.
  2. C wore the tie (clue 2), so the white sweater was A's.
  3. A is not Ribeiro (clue 1) and not Singh (clue 3), so A is Kumar — who indeed wears no jacket (clue 4).
  4. B wore the jacket. B is not Ribeiro, so B is Singh and C is Ribeiro.

Remember · 'Neither X nor Y' in a clue means X and Y are different people — a quiet but decisive fact in surname puzzles.

Question and answer: UPSC's official GS Paper II (2016, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

CSAT 2016 · Q55

Medium

Direction for the following 3 (three) items: Consider the given information and answer the three items that follow.

When three friends A, B and C met, it was found that each of them wore an outer garment of a different colour. In random order, the garments are: jacket, sweater and tie; and the colours are: blue, white and black. Their surnames in random order are: Ribeiro, Kumar and Singh.

Further, we know that:

1. neither B nor Ribeiro wore a white sweater

2. C wore a tie

3. Singh's garment was not white

4. Kumar does not wear a jacket

5. Ribeiro does not like to wear the black colour

6. Each of the friends wore only one outer garment of only one colour

What is the colour of the tie?

Answer & explanation

Answer: (b) Blue

C, who wore the tie, is Ribeiro. White is A's sweater, and Ribeiro does not wear black, so the tie must be blue.

  1. Clue 1 speaks of a white sweater worn by someone other than B and Ribeiro; it also tells us B is not Ribeiro.
  2. C wore the tie (clue 2), so the white sweater was A's.
  3. A is not Ribeiro (clue 1) and not Singh (clue 3), so A is Kumar — who indeed wears no jacket (clue 4).
  4. B wore the jacket. B is not Ribeiro, so B is Singh and C is Ribeiro.
  5. Ribeiro does not wear black (clue 5), so C's tie is blue and B's jacket is black.
  6. Result: A Kumar — white sweater; B Singh — black jacket; C Ribeiro — blue tie.

Remember · 'Neither X nor Y' in a clue means X and Y are different people — a quiet but decisive fact in surname puzzles.

Question and answer: UPSC's official GS Paper II (2016, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

CSAT 2016 · Q56

Medium

Direction for the following 3 (three) items: Consider the given information and answer the three items that follow.

When three friends A, B and C met, it was found that each of them wore an outer garment of a different colour. In random order, the garments are: jacket, sweater and tie; and the colours are: blue, white and black. Their surnames in random order are: Ribeiro, Kumar and Singh.

Further, we know that:

1. neither B nor Ribeiro wore a white sweater

2. C wore a tie

3. Singh's garment was not white

4. Kumar does not wear a jacket

5. Ribeiro does not like to wear the black colour

6. Each of the friends wore only one outer garment of only one colour

Who wore the sweater?

Answer & explanation

Answer: (a) A

Clue 1 points to a white sweater worn by neither B nor Ribeiro, and C wore the tie. So the sweater was A's.

  1. Clue 1 speaks of a white sweater worn by someone other than B and Ribeiro; it also tells us B is not Ribeiro.
  2. C wore the tie (clue 2), so the white sweater was A's.

Remember · 'Neither X nor Y' in a clue means X and Y are different people — a quiet but decisive fact in surname puzzles.

Question and answer: UPSC's official GS Paper II (2016, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

CSAT 2016 · Q58

Easy

A person walks 12 km due north, then 15 km due east, after that 19 km due west and then 15 km due south. How far is he from the starting point?

Answer & explanation

Answer: (a) 5 km

The moves net to 3 km south (12 north, 15 south) and 4 km west (15 east, 19 west) of the start. The straight-line distance is √(3² + 4²) = 5 km.

  1. North–south: 12 km north, then 15 km south → 3 km south.
  2. East–west: 15 km east, then 19 km west → 4 km west.
  3. Distance = √(3² + 4²) = √25 = 5 km.

Remember · Net out north–south and east–west moves separately, then apply Pythagoras once.

Question and answer: UPSC's official GS Paper II (2016, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

CSAT 2016 · Q61

Easy

A military code writes SYSTEM as SYSMET and NEARER as AENRER. Using the same code, FRACTION can be written as:

Answer & explanation

Answer: (d) CARFNOIT

The code splits a word into two halves and writes each half backwards: SYS|TEM becomes SYS|MET and NEA|RER becomes AEN|RER. So FRAC|TION becomes CARF|NOIT.

  1. SYSTEM = SYS | TEM; reversing each half gives SYS | MET = SYSMET.
  2. NEARER = NEA | RER; reversing each half gives AEN | RER = AENRER. The rule fits both.
  3. FRACTION = FRAC | TION; reversing each half gives CARF | NOIT = CARFNOIT.

Remember · In coding items, test a positional rule — halves, pairs, reversal — on every example given before applying it.

Question and answer: UPSC's official GS Paper II (2016, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

CSAT 2016 · Q74

Easy

In a class of 60 students, where the number of girls is twice that of boys, Kamal, a boy, ranked seventeenth from the top. If there are 9 girls ahead of Kamal, the number of boys in rank after him is:

Answer & explanation

Answer: (b) 12

The class has 20 boys and 40 girls. Of the 16 students ahead of Kamal, 9 are girls, so 7 are boys. Leaving out Kamal himself, 20 − 7 − 1 = 12 boys rank below him.

  1. Girls = 2 × boys and the total is 60, so boys = 20 and girls = 40.
  2. Kamal is 17th: 16 students are ahead; 9 are girls, so 7 are boys.
  3. Boys after Kamal = 20 − 7 − 1 = 12.

Remember · In ranking items, split the people ahead by group, then subtract them and the person himself from his group's total.

Question and answer: UPSC's official GS Paper II (2016, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

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