Question

B moves by taking 3 steps forward and 1 step backward (each step in one second ) he walks up a stationary escalator in 118 sec. However on moving escalator he takes 40 sec to reach top . Find speed of escalator.

Answer 1

Answer:

3.9 steps per sec

Step-by-step explanation:

B moves by taking 3 steps forward and 1 step backward (each step in one second ) he walks up a stationary escalator in 118 sec

Step moved in 4 sec = 3 - 1 = 2 step

Step moved in 116 sec = (116/4  )*2 = 236 step

+ 2 forward Steps in next 2 sec = 234 Steps

(no further back ward steps as he reached top)

in 40 sec

in 38 sec Steps moved = (38/4)*2 = 76 Step

+ 2 Forward steps in next 2 sec = 76 + 2 = 78 steps

Step by escalator in  40 Sec = 234 - 78 = 156 Steps

Speed of Escalator = 156/40 = 3.9 steps per sec