Filling a pool with a hose takes nine hours While draining The pool takes 14 hours. If the drain is open how long does to fill the pool in hours
Note that in one hour.....the portion of the pool that is filled = [1/9 - 1/14 ] =
[14 - 9 ] / [ 14* 9 ] =
5 / 126
The reciprocal of this tells us the number of hours it takes to fill the pool =
126/5 = 25 + 1/5 hours = 25 hours and 12 minutes
