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:

Pipe A can fill a tank in 3 hours. Pipe B can empty the same [#permalink]

Show Tags

27 May 2013, 03:16

4

This post was BOOKMARKED

00:00

A

B

C

D

E

Difficulty:

35% (medium)

Question Stats:

67% (01:15) correct
33% (01:06) wrong based on 293 sessions

HideShow timer Statistics

Pipe A can fill a tank in 3 hours. Pipe B can empty the same tank in 2 hours. If the tank is initially two thirds full then in how many hours will the tank be completely empty in if both the pipes are turned on simultaneously?

Re: Pipe A can fill a tank in 3 hours. Pipe B can empty the same [#permalink]

Show Tags

27 May 2013, 03:21

3

This post received KUDOS

gmatquant25 wrote:

Pipe A can fill a tank in 3 hours. Pipe B can empty the same tank in 2 hours. If the tank is initially two thirds full then in how many hours will the tank be completely empty in if both the pipes are turned on simultaneously? (A)2 hours (B)3 hours (C)4 hours (D)5 hours

Lets say tank contains 6 liters Pipe A works at \(\frac{6}{3}= 2\) liters every hour (added)=\(+2\) Pibe B works ar \(\frac{6}{2}= 3\) liters every hour (subtracted)=\(-3\)

The tank is 2/3 full so contains 4 liters, and the pipes combined give us a \(-3+2=-1\) liter every hour.(minus one liter every hour) So they would take \(4\) hours to empty it.
_________________

It is beyond a doubt that all our knowledge that begins with experience.

Pipe A can fill a tank in 3 hours. Pipe B can empty the same tank in 2 hours. If the tank is initially two thirds full then in how many hours will the tank be completely empty in if both the pipes are turned on simultaneously?

(A) 2 hours (B) 3 hours (C) 4 hours (D) 5 hours

The 2/3 of the tank will be emptied in \((time)=\frac{(job)}{(rate)}=\frac{\frac{2}{3}}{\frac{1}{2}-\frac{1}{3}}=4\) hours (1/2-1/3 is the rate at which the tank is emptied).

Re: Pipe A can fill a tank in 3 hours. Pipe B can empty the same [#permalink]

Show Tags

27 May 2013, 03:55

3

This post received KUDOS

Rate of filling the tank by A =1/3 Rate of emptying the tank by B =1/2 Combined rate of emptying the tank = 1/2-1/3 =1/6 2/3rd of tank needs to be emptied. R=w/t 1/6=(2/3)*(1/t) On simplifying , t= 4 hrs

Re: Pipe A can fill a tank in 3 hours. Pipe B can empty the same [#permalink]

Show Tags

27 Jun 2014, 06:57

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: Pipe A can fill a tank in 3 hours. Pipe B can empty the same [#permalink]

Show Tags

04 May 2016, 16:11

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: Pipe A can fill a tank in 3 hours. Pipe B can empty the same [#permalink]

Show Tags

20 May 2017, 10:34

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: Pipe A can fill a tank in 3 hours. Pipe B can empty the same [#permalink]

Show Tags

20 May 2017, 13:14

Consider the tank to be 180 units. Hence rate at which Pipe A fills the tank is 60 units(since it fills the tank in 3 hours) Also, rate at which Pipe B empties the tank is 90 units(since it empties the tank in 2 hours) It is given that the tank is 2/3rd's full or has 120 units of water in it.

We need to find the time to empty it completely given both the pipes are on. Both the pipes being on, will reduce 30 units(+60 - 90) an hour 120 - 30(x) = 0 or x=4(Option C)
_________________