Question

Jim can fill a pool carrying buckets of water in 30 minutes. Sue can do the same job in 45 minutes. Tony can do the same job in 1 ½ hours. How quickly can all three fill the pool together? ANYBODY KNOW THE ANSWER??

Answer 1

Jim's rate = Pool/30
Sue's rate = Pool/45
Tony's rate = Pool/90

combined rate = pool/30 + pool/45 + pool/90
= 6pool/90 = pool/15

So time working combined = pool/(pool/15) = 15

it will take 15 minutes.