Find all School-related info fast with the new School-Specific MBA Forum

 It is currently 28 Aug 2016, 04:01

### GMAT Club Daily Prep

#### 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

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

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

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

Author Message
TAGS:

### Hide Tags

Intern
Joined: 27 Mar 2013
Posts: 38
Followers: 0

Kudos [?]: 98 [0], given: 37

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

### Show Tags

27 May 2013, 03:16
2
This post was
BOOKMARKED
00:00

Difficulty:

45% (medium)

Question Stats:

66% (02:13) correct 34% (01:11) wrong based on 193 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?

(A) 2 hours
(B) 3 hours
(C) 4 hours
(D) 5 hours
(E) 9 hours
[Reveal] Spoiler: OA

Last edited by gmatquant25 on 27 May 2013, 03:30, edited 1 time in total.
VP
Status: Far, far away!
Joined: 02 Sep 2012
Posts: 1123
Location: Italy
Concentration: Finance, Entrepreneurship
GPA: 3.8
Followers: 173

Kudos [?]: 1798 [3] , given: 219

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
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.

Kant , Critique of Pure Reason

Tips and tricks: Inequalities , Mixture | Review: MGMAT workshop
Strategy: SmartGMAT v1.0 | Questions: Verbal challenge SC I-II- CR New SC set out !! , My Quant

Rules for Posting in the Verbal Forum - Rules for Posting in the Quant Forum[/size][/color][/b]

Math Expert
Joined: 02 Sep 2009
Posts: 34457
Followers: 6284

Kudos [?]: 79724 [3] , given: 10022

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

### Show Tags

27 May 2013, 03:32
3
KUDOS
Expert's post
2
This post was
BOOKMARKED
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

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).

Hope it's clear.
_________________
Current Student
Status: Final Lap Up!!!
Affiliations: NYK Line
Joined: 21 Sep 2012
Posts: 1095
Location: India
GMAT 1: 410 Q35 V11
GMAT 2: 530 Q44 V20
GMAT 3: 630 Q45 V31
GPA: 3.84
WE: Engineering (Transportation)
Followers: 38

Kudos [?]: 476 [3] , given: 70

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
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

Hope that helps!!!

Consider kudos if my post helps!!!
GMAT Club Legend
Joined: 09 Sep 2013
Posts: 11108
Followers: 511

Kudos [?]: 134 [0], given: 0

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.
_________________
GMAT Club Legend
Joined: 09 Sep 2013
Posts: 11108
Followers: 511

Kudos [?]: 134 [0], given: 0

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] 04 May 2016, 16:11
Similar topics Replies Last post
Similar
Topics:
6 Three pipes A, B and C can fill a tank in 6 hours. After working at i 3 10 Mar 2016, 19:31
19 Pipe A that can fill a tank in an hour and pipe B that can fill the 7 29 Aug 2014, 09:14
7 Pipe A can fill a tank in 32 minutes. Pipe B can fill the sa 7 08 Apr 2014, 08:30
9 One inlet pipe fills an empty tank in 5 hours. A second inle 7 11 Feb 2014, 00:51
2 Two pipes A and B can fill a tank in 8 hours. If only pipe A is open 10 05 May 2010, 18:47
Display posts from previous: Sort by