An escalator moves towards the top level at the rate of 12 ft.sec and its length is 160 feet. If a person walks on the moving escalator at the rate of 8 feet per second towards the top level, how much time does he take to cover the entire length.	Choose one
A) 10sec B) 8sec C) 9sec D) 7sec E) 12sec
Explanation :   Time taken to cover the entire length = tot.dist/resultant speed = 160/ (12+8)= 
<gadget id="calculator">160/ (12+8)</gadget>
<output>8</output>
8sec   Answer : 8sec
<result>B</result>
An escalator moves towards the top level at the rate of 12 ft.sec and its length is 160 feet. If a person walks on the moving escalator at the rate of 8 feet per second towards the top level, how much time does he take to cover the entire length.