SOLUTION: If Jill fills a pool with water in 30 min, jack fills a pool with water in 45 min and John fills a pool with water in 1 hour and 30 min. How long will it take if they work together

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Question 446383: If Jill fills a pool with water in 30 min, jack fills a pool with water in 45 min and John fills a pool with water in 1 hour and 30 min. How long will it take if they work together.
Found 2 solutions by stanbon, mananth:
Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website!
If Jill fills a pool with water in 30 min, jack fills a pool with water in 45 min and John fills a pool with water in 1 hour and 30 min. How long will it take if they work together.
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Jill rate = 1/30 job/min
Jack rate = 1/45 job/min
John rate = 1/90 job/min
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Together rate = 1/x job/min
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Equation:
rate + rate + rate = together rate
1/30 + 1/45 + 1/90 = 1/x
Multiply thru by 90x to get:
3x + 2x + x = 90
6x = 90
x = 15 minutes (time to fill the pool working together)
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Cheers,
Stan H.

Answer by mananth(16946) (Show Source):
You can put this solution on YOUR website!
Filling the pool is 1 job
Jill 0.5 hours
It does 2 jobs in 1 hours
Jack 0.75 hours
It does 1 1/ 3 of thejob in 1 hours
John 1.5 hours
It does 2/3 of the job in 1 hours

Together they will do 2 + 1.33 + 0.67
Together they will do 4 of the job in one hours
So they will take 1/4 hours
So they will take 0.25 hours