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:

Hose A runs at a constant rate and can fill a 11,000 gallon [#permalink]

Show Tags

17 Jan 2013, 10:25

3

This post was BOOKMARKED

00:00

A

B

C

D

E

Difficulty:

15% (low)

Question Stats:

75% (00:56) correct
25% (01:06) wrong based on 317 sessions

HideShow timer Statistics

Hose A runs at a constant rate and can fill a 11,000 gallon pool in 44 hours. How much less time would it take to fill the pool if Hose A and Hose B ran simultaneously at their respective constant rates?

(1) Both Hose A and Hose B can fill the same fraction of the pool in one hour. (2) It takes Hose B twice as long to fill the pool as it takes Hose A and Hose B running simultaneously to fill the pool.

Re: Hose A runs at a constant rate and can fill a 11,000 gallon [#permalink]

Show Tags

17 Jan 2013, 10:51

1

This post received KUDOS

shreerajp99 wrote:

Hose A runs at a constant rate and can fill a 11,000 gallon pool in 44 hours. How much less time would it take to fill the pool if Hose A and Hose B ran simultaneously at their respective constant rates?

1.Both Hose A and Hose B can fill the same fraction of the pool in one hour. 2.It takes Hose B twice as long to fill the pool as it takes Hose A and Hose B running simultaneously to fill the pool.

Work is 11000 gallon pool. Hose A rate rA can be established as 11,000/44 = some value Hose B rate rB is unknown?

1. It means that their rate is same for the fraction. We know the rate for rA and so rB can be found. Sufficient. 2. Relation between rB and rA. rA is known and can found rB. Sufficient.
_________________

Hose A runs at a constant rate and can fill a 11,000 gallon pool in 44 hours. How much less time would it take to fill the pool if Hose A and Hose B ran simultaneously at their respective constant rates?

1.Both Hose A and Hose B can fill the same fraction of the pool in one hour. 2.It takes Hose B twice as long to fill the pool as it takes Hose A and Hose B running simultaneously to fill the pool.

The concepts being tested here are:

1. Rates are additive. Rate of work of A and B working together is the sum of rates of A and B. i.e. Rate of work of A = R_A Rate of work of B = R_B Rate of work of both A and B working together = R_A + R_B

2. Work done = Rate * Time taken So if A and B do the same work, R_A*T_A = R_B*T_B R_A/R_B = T_B/T_A Ratio of their rates will be inverse of ratio of their time taken.

We are given the work done and time taken for hose A so we can find the rate of work for Hose A. (which is 11000/44 = 250 gallons/hr just for clarity) To find the time taken when both hoses work together, we need to find their combined rate of work. Hence we need to know the rate of work of Hose B too.

1.Both Hose A and Hose B can fill the same fraction of the pool in one hour. This tells us that their rate of work is the same. Rate of work of hose B = 250 gallons/hr too. When they work together, they will take half the usual time so they will take 22 hrs i.e. 22 hrs less. Sufficient.

2.It takes Hose B twice as long to fill the pool as it takes Hose A and Hose B running simultaneously to fill the pool. Time taken by B = 2*Time taken together Rate of B = 1/2 * Rate of working together (since ratio of rates is inverse) So Rate of B = Rate of A This boils down to statement 1 and hence is sufficient too.

Re: Hose A runs at a constant rate and can fill a 11,000 gallon [#permalink]

Show Tags

04 Mar 2013, 02:28

Hose A runs at a constant rate and can fill a 11,000 gallon pool in 44 hours. How much less time would it take to fill the pool if Hose A and Hose B ran simultaneously at their respective constant rates?

(1) Both Hose A and Hose B can fill the same fraction of the pool in one hour. This means they both have same rates (2) It takes Hose B twice as long to fill the pool as it takes Hose A and Hose B running simultaneously to fill the pool. Higher efficiency means lower no. of hrs i.e. twice efficiency means 1/2 the time required to fill i.e. 22 hrs. Now, we can find time taken by both A &B then can subtract _________________

Re: Hose A runs at a constant rate and can fill a 11,000 gallon [#permalink]

Show Tags

02 Apr 2013, 21:22

shreerajp99 wrote:

Hose A runs at a constant rate and can fill a 11,000 gallon pool in 44 hours. How much less time would it take to fill the pool if Hose A and Hose B ran simultaneously at their respective constant rates?

(1) Both Hose A and Hose B can fill the same fraction of the pool in one hour. (2) It takes Hose B twice as long to fill the pool as it takes Hose A and Hose B running simultaneously to fill the pool.

"(1) Both Hose A and Hose B can fill the same fraction of the pool in one hour."

This seems poorly worded to me. Why does the word "can" imply equivalent work rate? To me this means Hose B will the fill the 11,000 gallon pool IN AT LEAST 44 hours, thus Hose B rate is greater than or equal to Hose A rate. Just because Hose B CAN fill the pool at the same rate, doesn't mean that it WILL.

Hose A runs at a constant rate and can fill a 11,000 gallon pool in 44 hours. How much less time would it take to fill the pool if Hose A and Hose B ran simultaneously at their respective constant rates?

(1) Both Hose A and Hose B can fill the same fraction of the pool in one hour. (2) It takes Hose B twice as long to fill the pool as it takes Hose A and Hose B running simultaneously to fill the pool.

"(1) Both Hose A and Hose B can fill the same fraction of the pool in one hour."

This seems poorly worded to me. Why does the word "can" imply equivalent work rate? To me this means Hose B will the fill the 11,000 gallon pool IN AT LEAST 44 hours, thus Hose B rate is greater than or equal to Hose A rate. Just because Hose B CAN fill the pool at the same rate, doesn't mean that it WILL.

I chose B.

The question clearly states " ... Hose A and Hose B ran simultaneously at their respective constant rates?"

which means that hose A and hose B have their own constant rates at which they work. 'can' only implies that 'hose is able to complete this much work in this much time running at its constant rate'

On the same lines, you could also argue that 'Hose A runs at a constant rate and can fill a 11,000 gallon pool in 44 hours.' in the question talks about one possible rate of hose A but you are given that it runs at a constant rate.

I think you are reading too much in the word 'can'.
_________________

Re: Hose A runs at a constant rate and can fill a 11,000 gallon [#permalink]

Show Tags

22 May 2014, 21:11

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: Hose A runs at a constant rate and can fill a 11,000 gallon [#permalink]

Show Tags

29 Mar 2016, 04:45

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: Hose A runs at a constant rate and can fill a 11,000 gallon [#permalink]

Show Tags

20 May 2017, 11:28

VeritasPrepKarishma wrote:

shreerajp99 wrote:

Hose A runs at a constant rate and can fill a 11,000 gallon pool in 44 hours. How much less time would it take to fill the pool if Hose A and Hose B ran simultaneously at their respective constant rates?

1.Both Hose A and Hose B can fill the same fraction of the pool in one hour. 2.It takes Hose B twice as long to fill the pool as it takes Hose A and Hose B running simultaneously to fill the pool.

The concepts being tested here are:

1. Rates are additive. Rate of work of A and B working together is the sum of rates of A and B. i.e. Rate of work of A = R_A Rate of work of B = R_B Rate of work of both A and B working together = R_A + R_B

2. Work done = Rate * Time taken So if A and B do the same work, R_A*T_A = R_B*T_B R_A/R_B = T_B/T_A Ratio of their rates will be inverse of ratio of their time taken.

We are given the work done and time taken for hose A so we can find the rate of work for Hose A. (which is 11000/44 = 250 gallons/hr just for clarity) To find the time taken when both hoses work together, we need to find their combined rate of work. Hence we need to know the rate of work of Hose B too.

1.Both Hose A and Hose B can fill the same fraction of the pool in one hour. This tells us that their rate of work is the same. Rate of work of hose B = 250 gallons/hr too. When they work together, they will take half the usual time so they will take 22 hrs i.e. 22 hrs less. Sufficient.

2.It takes Hose B twice as long to fill the pool as it takes Hose A and Hose B running simultaneously to fill the pool. Time taken by B = 2*Time taken together Rate of B = 1/2 * Rate of working together (since ratio of rates is inverse) So Rate of B = Rate of A This boils down to statement 1 and hence is sufficient too.

Answer (D)

Hi Karishma ,

I have 1 doubt how Rb = 1/2 (Ra + Rb) converts to Rb = Ra in next step. (I dont think any where Rb+Ra= 2 Ra is given anywhere in prompt).

Version 8.1 of the WordPress for Android app is now available, with some great enhancements to publishing: background media uploading. Adding images to a post or page? Now...

Post today is short and sweet for my MBA batchmates! We survived Foundations term, and tomorrow's the start of our Term 1! I'm sharing my pre-MBA notes...

“Keep your head down, and work hard. Don’t attract any attention. You should be grateful to be here.” Why do we keep quiet? Being an immigrant is a constant...