Question

A man jumps 2 steps each time while climbing stairs. If he is standing at the 1st stair & jumps 31 times to reach the topmost stair, how many stairs did he jump?

• A. 60
• B. 62
• C. 64
• D. 65

Answer 1

The correct option is B 62

Here the person is jumping 2 steps at a time. And it is given he starts from the first step. So the set of steps he jumps will be

1,3,5,7,9,11,13,15,....

So here we can see the pattern is

The step he lands on= ($2^{\ast }$ number of jumps) + 1

So if he takes 31 jumps to reach the topmost step

Therefore the total number of steps = $2^{\ast }$31 +1 = 62 + 1 = 63