There are seven persons up on a ladder, A, B, C, D, E, F and G (not in that order). A is further up than E but is lower than C. B is in the middle. G is between A and B. E is between B and F. If F is between E and D, the person on the bottom step of the ladder will be
- (a) B
- (b) F
- (c) D ✓ UPSC's answer
- (d) E
Why the answer is (c)
• Number the steps 1 to 7 from bottom to top; B is in the middle, so B is on step 4.
• E is between B and F, so F and E are on opposite sides of B; if F were above B, E would be above B and F above E, leaving no higher steps for A and C because A must be above E and C above A.
• Therefore F is below B, so the order from bottom upward is D, F, E, B, because F is between E and D and E is between B and F.
• The remaining steps 5, 6 and 7 must hold G, A and C; G is between A and B, so G is on step 5 and A is above G.
• Since A is above E and below C, A must be on step 6 and C on step 7, making D the bottom step, so option (c) follows.
Why the other options are wrong
- (a) B
- B is on step 4, the middle step of the seven-step ladder, not the bottom step.
- (b) F
- F is on step 2, above D, in the forced lower order D, F, E, B.
- (d) E
- E is on step 3, above D and F, because E is between B and F with F below B.
Asked in the CSAT Paper II of the UPSC Civil Services Preliminary Examination 2014, held on 24 August 2014. Question and answer key: Union Public Service Commission. Explanation: UPSC Answer Check.