Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.
Customized for You
we will pick new questions that match your level based on your Timer History
Track Your Progress
every week, we’ll send you an estimated GMAT score based on your performance
Practice Pays
we will pick new questions that match your level based on your Timer History
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
It appears that you are browsing the GMAT Club forum unregistered!
Signing up is free, quick, and confidential.
Join other 500,000 members and get the full benefits of GMAT Club
Registration gives you:
Tests
Take 11 tests and quizzes from GMAT Club and leading GMAT prep companies such as Manhattan GMAT,
Knewton, and others. All are free for GMAT Club members.
Applicant Stats
View detailed applicant stats such as GPA, GMAT score, work experience, location, application
status, and more
Books/Downloads
Download thousands of study notes,
question collections, GMAT Club’s
Grammar and Math books.
All are free!
Thank you for using the timer!
We noticed you are actually not timing your practice. Click the START button first next time you use the timer.
There are many benefits to timing your practice, including:
DS: Pool Y and Pool X [#permalink]
07 Dec 2010, 07:21
1
This post received KUDOS
8
This post was BOOKMARKED
00:00
A
B
C
D
E
Difficulty:
35% (medium)
Question Stats:
72% (02:01) correct
28% (01:12) wrong based on 329 sessions
If Pool Y currently contains more water than Pool X, and if Pool X is currently filled to 2/7 of its capacity, what percent of the water currently in Pool Y needs to be transferred to Pool X if Pool X and Pool Y are to have equal volumes of water?
(1) If all the water currently in Pool Y were transferred to Pool X, Pool X would be filled to 6/7 of its capacity.
I came across this DS question on my last MgCAT, and while I do understand how to solve it, I fail to see why (according to the Mg explanation) we should consider both pools capacity as equal, when nothing in the text leads to that assumption… (or am I missing something here?)
Re: Can someone clear out this DS question for me plz. [#permalink]
07 Dec 2010, 08:10
5
This post received KUDOS
Expert's post
1
This post was BOOKMARKED
itnas wrote:
Hi.
I came across this DS question on my last MgCAT, and while I do understand how to solve it, I fail to see why (according to the Mg explanation) we should consider both pools capacity as equal, when nothing in the text leads to that assumption… (or am I missing something here?)
Therefore I felt for E.
Thanks for the help.
If Pool Y currently contains more water than Pool X, and if Pool X is currently filled to 2/7 of its capacity, what percent of the water currently in Pool Y needs to be transferred to Pool X if Pool X and Pool Y are to have equal volumes of water?
(1) If all the water currently in Pool Y were transferred to Pool X, Pool X would be filled to 6/7 of its capacity.
(2) Pool X has a capacity of 14,000 gallons.
We are nowhere told that the capacities of pools X and Y are equal.
(1) If all the water currently in Pool Y were transferred to Pool X, Pool X would be filled to 6/7 of its capacity --> together pools X and Y contain 6/7 of the capacity of pool X. Now, in order pools X and Y to contain equal amount of water each pool should contain 3/7 of the capacity of pool X, thus from pool Y, which contains 4/7 (6/7-2/7=4/7) of the capacity of pool X we must transfer 1/7 of the capacity of pool X, which is 25% of the water currently in pool Y (1/7)/(4/7)=1/4. Sufficient.
Or consider the following: Let the capacity of pool X be 7 gallons. It's 2/7 full, thus there are 2 gallons of water. If all the water currently in Pool Y were transferred to Pool X, Pool X would be filled to 6/7 of its capacity and thus will contain 6 gallons of water, which means that there are now 6-2=4 liters of water in pool Y (it doesn't matter what capacity it has). In order both pools to contain equal amount of water each pool should contain 3 gallons of water, thus we should transfer 1 gallon from pool Y to pool X. 1 gallon is 1/4 of the water currently in pool Y.
(2) Pool X has a capacity of 14,000 gallons. No info about pool Y. Not sufficient.
Question: Let the capacity of X be C so, X= 2C/7 and Y>X If n is the quantity of water taken from Y and put into X Then, Y-n = X+n 2n = Y-X => n = (Y-X)/2 n is the quantity that needs to be transferred. The % will (n/Y) * 100 % (Note, that we already have one equation with X and C, and we just need one more involving Y and C, if we can get it out of any of the statements, it should be enough to solve) Now lets take a look at the statements :
(1) If all the water currently in Pool Y were transferred to Pool X, Pool X would be filled to 6/7 of its capacity.
Y+X = 6C/7 and we know that X=2C/7
Hence, Y=4C/7
n = (Y-X)/2 = C/7 Therefore, % of water = (C/7)/(4C/7) *100 =100/4 =25%
Sufficient.
(2) Pool X has a capacity of 14,000 gallons.
We need another relation in Y and C or Y and X to be able to solve, not sufficient.
Ans: A _________________
PS: Like my approach? Please Help me with some Kudos.
Re: If Pool Y currently contains more water than Pool X, and if [#permalink]
13 Sep 2014, 21:23
Hello from the GMAT Club BumpBot!
Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).
Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email. _________________
Re: If Pool Y currently contains more water than Pool X, and if [#permalink]
15 Jan 2016, 02:21
Hello from the GMAT Club BumpBot!
Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).
Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email. _________________
The “3 golden nuggets” of MBA admission process With ten years of experience helping prospective students with MBA admissions and career progression, I will be writing this blog through...
You know what’s worse than getting a ding at one of your dreams schools . Yes its getting that horrid wait-listed email . This limbo is frustrating as hell . Somewhere...