Question

One pump can fill a swimming pool in 8 hours and another pump can fill it in 10 hours. If both pumps are opened at the same time, how many hours will it take to fill the pool?

Answer 1

Answer: It will take
`(40)/(9)=4(4)/(9)` hours to fill the pool.

Explanation:

Since we have given that

Number of hours first pump takes = 8 hours

Number of hours second pump takes = 10 hours

If both pumps are opened at the same time,

Work done by first pump =
`(1)/(8)`

Work done by second pump =
`(1)/(10)`

According to question,we get that

`(1)/(8)+(1)/(10)\\\\=(5+4)/(40)\\\\=(9)/(40)`

So, it will take
`(40)/(9)=4(4)/(9)` hours to fill the pool.