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humans
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nookway
The answer is E.

Excellent explanation nookway. Thanks.
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I agree. Great explanation. I tried to solve this problem the following way (which is wrong I guess). However, I cannot figure out why. HELP :)

1) Determine the time pump A would need to fill the pool alone:

A+B=6/5
A+C=3/2
C+B=2

Solve for A=7/20 hours

2) Use the combined rate for C+ B and the rate for A and solve for the combined rate of A, B, C:

1/x = 1/2 + 20/7 = 47/14

So where did I go wrong?! Thank you very much for your help!

Steve
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I agree. Great explanation. I tried to solve this problem the following way (which is wrong I guess). However, I cannot figure out why. HELP :)

1) Determine the time pump A would need to fill the pool alone:

A+B=6/5
A+C=3/2
C+B=2

Solve for A=7/20 hours

So where did I go wrong?! Thank you very much for your help!

Steve

Steve,

Here you are making the mistake of adding the times of A+B, A+C, C+B to calculate the time for A. You need to add the rates.

Here is a link that explains it quite well.

https://www.algebra.com/algebra/homework ... ems.lesson

Hope this helps.

Regards,

Nookway
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Rate for filling 1 pool.
A+B=5/6
A+C=2/3
B+C=1/2

Sum=(2A+2B+2C)= 12/6=2
A+B+C=1

Hence 1 hr.
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ira has the easiest way of doing it, don't make it overcomplicated.....just remember to flip them all and make them a reciprocal. When I first started doing these problems, it drove me nuts, but when I got it - it made it so much easier.....



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