SOLUTION: An inlet pipe on a swimming pool can be used to fill the pool in 6 hours. The drain pipe can be used to empty the pool in 12 hours. If the pool is 14 filled and then the inlet p

Question 965451: An inlet pipe on a swimming pool can be used to fill the pool in
6 hours. The drain pipe can be used to empty the pool in
12 hours. If the pool is
14 filled and then the inlet pipe and drain pipe are opened, how long from that time will it take to fill the pool?
Found 2 solutions by macston, josgarithmetic:
Answer by macston(5194) (Show Source): You can put this solution on YOUR website!
.
The inlet fills 1 pool /6 hours=(1/6) pool/hr
.
The drain empties -1 pool /12 hours=-(1/12) pool/hour
.
Net change with both open=+(1/6) pool/hr-(1/12) pool/hr=+(1/12) pool/hr
With both open. the pool fills at a rate of 1/12 pool/hr.
.
If the pool is 1/4 (3/12) full, that leaves ((1)-(3/12)=9/12) 9/12 pool to fill, at a rate of 1/12 pool/hr it will take 9 hours.
ANSWER: With both pipes open, it takes 9 hours to fill 3/4 of the pool.

Answer by josgarithmetic(39616) (Show Source): You can put this solution on YOUR website!
INLET

DRAIN

INLET & DRAIN WORKING SIMULTANEOUSLY

POOLS per HOUR

, POOLS per HOUR

"...the pool is 14 filled...", means nothing without the needed unit. Hopefully you mean, "14 percent". No volume measures were given or used.
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