Math
posted by Anonymous on .
Jim can fill a pool in 30 min, sue can do it in 45 min, Tony can do it in 90min, how long would it take all three to fill the pool together? How would i figure this out?

See Related Questions below.

Jim's rate = pool/30
Sue's rate = pool/45
Tony'rate = pool/90
combined rate = pool/30 + pool/45 + pool/90
= (3pool + 2pool + pool)/90 = 6pool/90
= 2pool/30
time to fill pool with combined rate
= pool/(2pool/30)
= 1/(2/30)
= 15 
Im still not sure how you are geting the (3pool+2pool+pool) where are those numbers coming from?

Jim can fill 3 pools in 90 minutes; Sue fills 2 pools in 90 minutes . . .

oh wow thank you so much i totally understand now

You're very welcome.