UPSC Prelims 2017 CSAT Paper II · Q36 of 79 Logical Reasoning medium

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

  1. (a) A, B and C
  2. (b) B, C and F ✓ UPSC's answer
  3. (c) A, B and F
  4. (d) A, C and F

Why the answer is (b)

['- Initial state: All six boys (A, B, C, D, E, F) start with 10 cards each.', '- F borrows 2 from A: A has 8, F has 12.', '- F gives 5 to C: F has 7, C has 15.', '- C gives 3 to B: C has 12, B has 13.', '- B gives 6 to D: B has 7, D has 16.', '- D passes 1 to E: D has 15, E has 11. The sum of cards for D and E is 15 + 11 = 26. The sum for B, C, and F is 7 + 12 + 7 = 26, which matches the key option (b).']

Why the other options are wrong

(a) A, B and C
The sum of cards for A, B, and C is 8 + 7 + 12 = 27, which is not equal to 26.
(c) A, B and F
The sum of cards for A, B, and F is 8 + 7 + 7 = 22, which is not equal to 26.
(d) A, C and F
The sum of cards for A, C, and F is 8 + 12 + 7 = 27, which is not equal to 26.

Asked in the CSAT Paper II of the UPSC Civil Services Preliminary Examination 2017, held on 18 June 2017. Question and answer key: Union Public Service Commission. Explanation: UPSC Answer Check.

Reading the answer is not the same as getting it right under a clock. Practise this question with UPSC's negative marking, and anything you miss goes into an error notebook until you get it right twice.

Practise this paper free