Question

A pool can be filled by one particular pipe in 10 hours, whereas a different pipe requires 6 hours to fill the same pool. How long would it take to fill the pool with both pipes turned on?

Answer 1

In one hour the first pipe fills 1/10 of total.

In one hour the second pipe fills 1/6 of total.

One hour with both pipes turned on fills:

`(1)/(10)+(1)/(6)=(16)/(60)=(8)/(30)=(4)/(15)`

fills 4/15 on one hour, then to fully fill the pool with both pipes turned on we need:

`(1)/((4)/(15))=(15)/(4)=3.75`

3 hours and 45 minutes.