SOLUTION: One pump can empty a pool in 5 days, whereas a second pump can empty the pool in 7 days. How long will it take the two pumps, working together, to empty the pool?

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: One pump can empty a pool in 5 days, whereas a second pump can empty the pool in 7 days. How long will it take the two pumps, working together, to empty the pool?       Log On


   

Question 428523: One pump can empty a pool in 5 days, whereas a second pump can empty the pool in 7 days. How long will it take the two pumps, working together, to empty the pool?
Answer by mananth(16946) About Me  (Show Source):
You can put this solution on YOUR website!
Emptying the tank is one job
one pipe drains in 5 days
It does 1/ 5 of the job in 1 day
other pipe 7 day
It does 1/ 7 of thejob in 1 day
Together they will do 1/5+ 1/ 7
Together they will do 12/35 of the job in one day
So they will take 2 8/9 days
So they will take 2.92 days