UPSC Prelims 2017 · CSAT
Question 59: Logical Reasoning and Mental Ability
Consider the following : A, B, C, D, E, F, G and H are standing in a row facing North. B is not neighbour of G. F is to the immediate right of G and neighbour of E. G is not at the extreme end. A is sixth to the left of E. H is sixth to the right of C. Which one of the following is correct in respect of the above?
AnswerUPSC’s answer is (c).
Number the places 1 to 8 from the left. A is six places left of E, so (A, E) is (1, 7) or (2, 8). H is six places right of C, so (C, H) is (1, 7) or (2, 8). Taking A = 2, E = 8 forces C = 1, H = 7, leaving no place for F beside E, so it fails. Hence A = 1, E = 7, C = 2, H = 8. F must be right of G and next to E, so F = 6 and G = 5. B is not next to G, so B = 3 and D = 4. The row is A C B D G F E H.
Why each option is right or wrong
- (a) C is at place 2, to the right of A at place 1, not the left.
- (b) D at place 4 is beside B and G, not F.
- (c) Correct: D is at place 4 and G is at place 5.
- (d) A is at place 1, but E is at place 7 and H at 8, so E is not at an end.
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.