SOLUTION: a pipe can fill a pool in 9 hours, while a drain can empty it in 15 hours. if the pipe and drain were both opened at 12 noon, then at what time will the pool be filled?

Algebra ->  Equations -> SOLUTION: a pipe can fill a pool in 9 hours, while a drain can empty it in 15 hours. if the pipe and drain were both opened at 12 noon, then at what time will the pool be filled?      Log On


   



Question 1120279: a pipe can fill a pool in 9 hours, while a drain can empty it in 15 hours. if the pipe and drain were both opened at 12 noon, then at what time will the pool be filled?
Found 2 solutions by josgarithmetic, Shin123:
Answer by josgarithmetic(39620) About Me  (Show Source):
You can put this solution on YOUR website!
1%2F9-1%2F15
%281%2F9%29%285%2F5%29-%281%2F15%29%283%2F3%29
5%2F45-3%2F45
2%2F45
-
45%2F2
highlight%2822%261%2F2%29
10:30AM the next day

Answer by Shin123(626) About Me  (Show Source):
You can put this solution on YOUR website!
The pipe can fill 1/9 of the pool in a hour and the drain can “fill” -1/15 of the pool in a hour.
1%2F9-1%2F15
5%2F45-3%2F45=2%2F45 The pipe and the drain can fill 2/45 of the pool in a hour.
1%2F%282%2F45%29=45%2F2=22%261%2F2 10:30 AM the next day, the pool will be full.