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# A pipe fills a pool in 3.5 hours. If the flow of water is changed so

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Joined: 02 Sep 2009
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A pipe fills a pool in 3.5 hours. If the flow of water is changed so  [#permalink]

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03 Oct 2016, 23:33
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5% (low)

Question Stats:

87% (01:26) correct 13% (01:46) wrong based on 190 sessions

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A pipe fills a pool in 3.5 hours. If the flow of water is changed so that the pipe's rate is halved, then how long will it take for the pipe to fill 2/3 of the pool?

A. 4 hours and 40 minutes
B. 3 hours and 10 minutes
C. 2 hours and 20 minutes
D. 7 hours
E. 2/21 hours

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Re: A pipe fills a pool in 3.5 hours. If the flow of water is changed so  [#permalink]

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04 Oct 2016, 02:49
Bunuel wrote:
A pipe fills a pool in 3.5 hours. If the flow of water is changed so that the pipe's rate is halved, then how long will it take for the pipe to fill 2/3 of the pool?

A. 4 hours and 40 minutes
B. 3 hours and 10 minutes
C. 2 hours and 20 minutes
D. 7 hours
E. 2/21 hours

A pipe fills a pool in 3.5 hours and now the pipe's rate is halved...so it'll take double the actual time to fill the tank i.e 7 hours... then in 1 hour we get 1/7th of the tank..

we need to find how long does it take to fill 2/3 of pool

W = RT

2/3 = 1/7* T => T =14/3 = 4.6..

IMO option A.
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Re: A pipe fills a pool in 3.5 hours. If the flow of water is changed so  [#permalink]

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04 Oct 2016, 02:55
A
a pipe takes 3.5 hrs to fill the tank. So when rate is reduced to half it will take 7 hrs to fill the tank.
so time time taken to fill 2/3rd tank capacity is given by 7*2/3=4 hrs 40min
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Re: A pipe fills a pool in 3.5 hours. If the flow of water is changed so  [#permalink]

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05 Oct 2016, 04:58
Bunuel wrote:
A pipe fills a pool in 3.5 hours. If the flow of water is changed so that the pipe's rate is halved, then how long will it take for the pipe to fill 2/3 of the pool?

A. 4 hours and 40 minutes
B. 3 hours and 10 minutes
C. 2 hours and 20 minutes
D. 7 hours
E. 2/21 hours

Rate R................. 1 pool ................... 3.5 hrs
Rate R/2............. 2/3 pool................. ?? hrs

No of hours = 3.5 * (2/3) * R/(R/2) = 4(2/3) hrs

For more on this, check: https://www.veritasprep.com/blog/2013/0 ... variation/
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Re: A pipe fills a pool in 3.5 hours. If the flow of water is changed so  [#permalink]

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29 May 2018, 09:23
Bunuel wrote:
A pipe fills a pool in 3.5 hours. If the flow of water is changed so that the pipe's rate is halved, then how long will it take for the pipe to fill 2/3 of the pool?

A. 4 hours and 40 minutes
B. 3 hours and 10 minutes
C. 2 hours and 20 minutes
D. 7 hours
E. 2/21 hours

The initial rate for the pool is 1/3.5, so when the rate is halved the new rate is 1/7.

So it will take (2/3)/(1/7) = 14/3 = 4 2/3 hours = 4 hours and 40 minutes.

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Re: A pipe fills a pool in 3.5 hours. If the flow of water is changed so  [#permalink]

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03 Oct 2018, 01:15
A pipe fills a pool in an hour= 1/3.5
After rate is halved, A pipe fills a pool in an hour= 1/3.5*2= 1/7
So, After rate is halved, pipe takes time to fill pool= 7 hrs
So, After rate is halved, pipe takes time to fill 2/3 pool= 7*2/3 hrs= 4 hours and 40 mins

(A)
Re: A pipe fills a pool in 3.5 hours. If the flow of water is changed so   [#permalink] 03 Oct 2018, 01:15
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