A man walks up an escalator, taking one step per second. After taking thirty steps, he is at the top.

Next day, he goes up at two steps per second, reaching the top in 36 steps.

The third day, he has had a long afternoon and merely sits on the escalator, waiting for it to reach the top.

How long does it take him?

let n be the no of the steps when the man gets on the escalator and p be the rate at which the escalator is moving(in steps/sec). so you get:
n = 30 + 30p & n = 36 + 18p.
on solving n=45 and p=.5.
required time = n/p = 90secs.

Posted by spinoza on 2003-06-02 10:32:11