Question

A person walks up a stalled escalator in 90 sec. When
standing on the same escalator now moving, he is carried
in 60s. The time he would take to walk up the moving
escalator will be :-​

Answer 1

Explanation:

take distance of escalator= d

1. Speed of man= Sm= d/90

2. speed of escalator= Se= d/60

total time taken to walk up escalator is = T

now time take to walk up the moving escalator=

Sm+Se=d/90+d/60

d/T= d/90+d/60

d/T= d(90+60/90x60)

T = 90x60/90+60

T = 5400/150

T = 36 sec