UPSC Prelims 2017 · CSAT
Question 36: Logical Reasoning and Mental Ability
Six boys A, B, C, D, E and F play a game of cards. Each has a pack of 10 cards. F borrows 2 cards from A and gives away 5 to C who in turn gives 3 to B while B gives 6 to D who passes on 1 to E. Then the number of cards possessed by D and E is equal to the number of cards possessed by
AnswerUPSC’s answer is (b).
Start with 10 cards each. F takes 2 from A: A 8, F 12. F gives 5 to C: F 7, C 15. C gives 3 to B: C 12, B 13. B gives 6 to D: B 7, D 16. D gives 1 to E: D 15, E 11. D + E = 26. Now find the trio with 26 cards: B + C + F = 7 + 12 + 7 = 26.
Why each option is right or wrong
- (a) A + B + C = 8 + 7 + 12 = 27.
- (b) Correct: B + C + F = 7 + 12 + 7 = 26.
- (c) A + B + F = 8 + 7 + 7 = 22.
- (d) A + C + F = 8 + 12 + 7 = 27.
Answer: UPSC’s key. Explanation: written by UPSC Grade, not by UPSC.
Source: UPSC, Civil Services (Preliminary) Examination 2017, General Studies Paper II (CSAT), Series A. The paper on upsc.gov.in.