With both valves open

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With both valves open

by nhai2003 » Sat Jul 11, 2009 1:59 am
With both valves open, the pool will be filled with water in 48 minutes. The first valve alone would fill the pool in 2 hours. What is the capacity of the pool if every minute the second valve admits 50 cubic meters of water more than the first?

9000 cubic meters
10500 cubic meters
11750 cubic meters
12000 cubic meters
12500 cubic meters

:roll:

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by gmat740 » Sat Jul 11, 2009 2:40 am
Hey you need to do a small correction. I hope I am correct,because that is the only way I figured out this question can be solved.
What is the capacity of the pool if every minute the second valve admits 50 cubic meters of water more than the first?
I think this would be reverse : if every minute the first valve admits 50 cubic meters of water more than the second?
IMO 12000

A(1st valve) can fill in 2 hrs
together = 48 mints =4/5 hrs

1/a + 1/b = 5/4

1/2 +1/b = 5/4

b= 4 hrs
b= second valve
Now its given
every minute the first valve admits 50 cubic meters of water more than the second

Since A can fill in 2 hrs,so definitely speed of A is higher than that of B

If B has speed of V
Speed of A =2V

Now look at what's the condition

2v = v+50

v= 50

capacity of pool = speed of B* time taken by B
= 50*4hrs*60(speed is given per minute)
=12000

Hope this helps

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by nhai2003 » Sat Jul 11, 2009 5:06 am
GMAT740: Thanks for your explanation!

there is no typo.