A person is standing on the first step from the bottom of a ladder. If he has to climb 4 more steps to reach exactly the middle step, how many steps does the ladder have ?
- (a) 8
- (b) 9 ✓ UPSC's answer
- (c) 10
- (d) 11
Why the answer is (b)
• The person is currently on the 1st step from the bottom.
• Climbing 4 more steps places him on the 1 + 4 = 5th step.
• The problem states that the 5th step is exactly the middle step of the ladder.
• For a step to be the exact middle, the number of steps below it must equal the number of steps above it.
• Since there are 4 steps below the 5th step, there must be 4 steps above it.
• Total steps = 4 (below) + 1 (middle) + 4 (above) = 9 steps.
Why the other options are wrong
- (a) 8
- 8 steps would make the middle point between the 4th and 5th steps, not a single step.
- (c) 10
- 10 steps would make the middle point between the 5th and 6th steps, not a single step.
- (d) 11
- 11 steps would make the 6th step the middle, not the 5th step.
Asked in the CSAT Paper II of the UPSC Civil Services Preliminary Examination 2016, held on 7 August 2016. Question and answer key: Union Public Service Commission. Explanation: UPSC Answer Check.