UPSC Prelims 2014 · CSAT
Question 11: Logical Reasoning and Mental Ability
Four children are sitting in a row. A is occupying the seat next to B but not next to C. If C is not sitting next to D, who is/are occupying seat/seats adjacent to D ?
AnswerUPSC’s answer is (b).
C can sit next to neither A nor D, so C's only possible neighbour is B. A is also next to B, so B has C on one side and A on the other: C, B, A. D must then take the remaining seat, at the end beside A. The row reads C, B, A, D (or its mirror image), so only A is adjacent to D. Start such puzzles with the person who has the most restrictions.
Why each option is right or wrong
- (a) B sits between C and A, nowhere near D.
- (b) Right. D is at the end, next to A only.
- (c) B is not adjacent to D.
- (d) The conditions fix the arrangement, so it can be told.
Answer: UPSC’s key. Explanation: written by UPSC Grade, not by UPSC.
Source: UPSC, Civil Services (Preliminary) Examination 2014, General Studies Paper II (CSAT), Series A. The paper on upsc.gov.in.