SOLUTION: 3. 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 � hours. How quickly can all three fill the poo

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Question 340393: 3. 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 � hours. How quickly can all three fill the pool together?
A. 12 minutes
B. 15 minutes
C. 21 minutes
D. 23 minutes
E. 28 minutes
Answer by solver91311(24713) (Show Source):
You can put this solution on YOUR website!

If A can do a job in x time periods, then A can do of the job in 1 time period. Likewise, if B can do the same job in y time periods, then B can do of the job in 1 time period.

So, working together, they can do

of the job in 1 time period.

Therefore, they can do the whole job in:

time periods.

This idea is easily expanded to three workers:

and so on...

Don't for get to change Tony's "do it by himself" time from 1 and 1/2 hours to 90 minutes so that you are working with the same time units for all three people.

John

My calculator said it, I believe it, that settles it