Question

An escalator is descending at constant speed. A walks down and takes 50 steps to reach the bottom. B runs down and takes 90 steps in the same time as A takes 10 steps. How many steps are visible when the escalator is not operating?

Answer 1

Answer:

total number of steps on escalator is 100.

Step-by-step explanation:

Lets suppose that A walks down 1 step / min and

escalator moves n steps/ min

It is given that A takes 50 steps to reach the bottom

In the same time escalator would have covered 50n steps

So total steps on escalator is 50 + 50n.

Again it is given that B takes 90 steps to reach the bottom and time  

taken by him for this is equal to time taken by A to cover 10 steps i.e  

10 minutes. So in this 10 min escalator would have covered 10n steps.

So total steps on escalator is 90 + 10n

Again equating 50 + 50n = 90 + 10n we get n = 1

Hence total number of steps on escalator is 100.