An escalator moves towards the top level at the rate of 11 ft.sec and its length is 140 feet. If a person walks on the moving escalator at the rate of 3 feet per second towards the top level, how much time does he take to cover the entire length. Choose the correct choice from the following options: A) 14 sec B) 10 sec C) 12 sec D) 8 sec E) 5 sec

Rationale: explanation : time taken to cover the entire length = tot . dist / resultant speed = 140 / ( 11 + 3 ) = 10 sec answer : b
Answer: B