SOLUTION: how long will it take 3 pumps to empty a pool working together? pump one can empty in 5days, pump two 7 days and pump three 4 days.

Algebra ->  Rate-of-work-word-problems -> SOLUTION: how long will it take 3 pumps to empty a pool working together? pump one can empty in 5days, pump two 7 days and pump three 4 days.      Log On


   

Question 782299: how long will it take 3 pumps to empty a pool working together?
pump one can empty in 5days, pump two 7 days and pump three 4 days.
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
1%2F5+%2B+1%2F7+%2B+1%2F4+=+1%2Ft

28%2F140+%2B+20%2F140+%2B+35%2F140+=+1%2Ft

%2828+%2B+20+%2B+35%29%2F140+=+1%2Ft

83%2F140+=+1%2Ft

83t+=+140

t+=+140%2F83

t+=+1.68674 Use a calculator to get 140/83 = 1.68674 (roughly)

It will take approximately 1.68674 days if the 3 pumps work together.