Two pumps working together drain a pool in #6# hours. If older pump itself drains out the pool in #14# hours, how much time will newer pump take to drain the pool?

1 Answer
Feb 22, 2017

Answer:

Newer pump can drain out the pool in #10 1/2# hours.

Explanation:

As two pumps working together drain the pool in #6# hours,

in one hour, they drain #1/6# of the pool.

As older pump itself drains the pool in #14# hours

as such in one hour, older pump can drain #1/14# of the pool.

As in one hour, two pumps together drain out #1/6# of the pool and older pump drains out #1/14# of the pool

newer pump on its own must be draining

#1/6-1/14=(7-3)/42=4/42=2/21# of the pool

Hence, newer pump can drain out the pool in #21/2=10 1/2# hours.