SOLUTION: One pump can drain a pool in 11 minutes. When a second pump is also used, the pool only takes 3 minutes to drain. How long would it take the second pump to drain the pool if it wer

Algebra ->  Rate-of-work-word-problems -> SOLUTION: One pump can drain a pool in 11 minutes. When a second pump is also used, the pool only takes 3 minutes to drain. How long would it take the second pump to drain the pool if it wer      Log On


   



Question 591603: One pump can drain a pool in 11 minutes. When a second pump is also used, the pool only takes 3 minutes to drain. How long would it take the second pump to drain the pool if it were the only pump in use?
Answer by nerdybill(7384) About Me  (Show Source):
You can put this solution on YOUR website!
One pump can drain a pool in 11 minutes. When a second pump is also used, the pool only takes 3 minutes to drain. How long would it take the second pump to drain the pool if it were the only pump in use?
.
Let x = time (minutes) for second pump alone
then
3(1/11 + 1/x) = 1
multiplying both sides by 11x:
3(x + 11) = 11x
3x + 33 = 11x
33 = 8x
33/8 = x
4.125 mins = x
or
4 mins 7.5 secs = x