SOLUTION: pump A can fill a pool in 11 hrs and pump B can empty the same pool in 4 hrs. accidentally, both the pumps started at the same time. how long it will take to empty the pool?

Algebra ->  Rate-of-work-word-problems -> SOLUTION: pump A can fill a pool in 11 hrs and pump B can empty the same pool in 4 hrs. accidentally, both the pumps started at the same time. how long it will take to empty the pool?      Log On


   

Question 841532: pump A can fill a pool in 11 hrs and pump B can empty the same pool in 4 hrs. accidentally, both the pumps started at the same time. how long it will take to empty the pool?
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
Rate of emptying is 1%2F4-1%2F11 pools per hour.

%281%2F4%29%2811%2F11%29-%281%2F11%29%284%2F4%29
7%2F44 pools per hour or 44%2F7=6%263%2F7 HOURS per POOL.