GMAT Question of the Day - Daily to your Mailbox; hard ones only

It is currently 18 Sep 2018, 20:40

Close

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
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.

Close

Request Expert Reply

Confirm Cancel

Pumping alone at their respective constant rates, one inlet pipe fills

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:

Hide Tags

Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 49208
Pumping alone at their respective constant rates, one inlet pipe fills  [#permalink]

Show Tags

New post 16 Oct 2015, 07:31
4
4
00:00
A
B
C
D
E

Difficulty:

  5% (low)

Question Stats:

90% (01:13) correct 10% (01:56) wrong based on 306 sessions

HideShow timer Statistics

Pumping alone at their respective constant rates, one inlet pipe fills an empty tank to 1/2 of capacity in 3 hours and a second inlet pipe fills the same empty tank to 2/3 of capacity in 6 hours. How many hours will it take both pipes, pumping simultaneously at their respective constant rates, to fill the empty tank to capacity?

(A) 3.25
(B) 3.6
(C) 4.2
(D) 4.4
(E) 5.5

Kudos for a correct solution.

_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

Collection of Questions:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics

Director
Director
User avatar
G
Joined: 20 Feb 2015
Posts: 728
Concentration: Strategy, General Management
Premium Member CAT Tests
Re: Pumping alone at their respective constant rates, one inlet pipe fills  [#permalink]

Show Tags

New post 16 Oct 2015, 07:48
2
pipe 1 = 1/6 an hour
pipe 2 = 1/9 an hour

Total time taken =1/6 + 1/9 =3.6 Hours
Intern
Intern
User avatar
Status: GMAT1:520 Q44 V18
Joined: 03 Sep 2015
Posts: 11
Location: United States
Concentration: Strategy, Technology
WE: Information Technology (Computer Software)
Re: Pumping alone at their respective constant rates, one inlet pipe fills  [#permalink]

Show Tags

New post 16 Oct 2015, 08:06
2
Tank A does 1/2 in 3 hrs so we can fine for full capacity it would take 6 hrs.
Similarly , Tank B takes 2/3rd of tank to be filled in 6 hrs so it would fill to full capacity in 6/(2/3) =>18/2 => 9

Now simple work problem states that it would fill the whole tank in :

1/9 + 1/6 = 5/18 unit =>18/5 hrs = 3.6 hrs

Hence Option B
Board of Directors
User avatar
P
Joined: 17 Jul 2014
Posts: 2697
Location: United States (IL)
Concentration: Finance, Economics
GMAT 1: 650 Q49 V30
GPA: 3.92
WE: General Management (Transportation)
GMAT ToolKit User Premium Member Reviews Badge
Re: Pumping alone at their respective constant rates, one inlet pipe fills  [#permalink]

Show Tags

New post 16 Oct 2015, 08:10
1
agree with the above solutions. Answer B is correct.
Current Student
User avatar
Joined: 29 Mar 2015
Posts: 77
Concentration: Strategy, Operations
GMAT 1: 700 Q51 V33
WE: Research (Other)
GMAT ToolKit User Reviews Badge
Re: Pumping alone at their respective constant rates, one inlet pipe fills  [#permalink]

Show Tags

New post 17 Oct 2015, 04:48
1
Bunuel wrote:
Pumping alone at their respective constant rates, one inlet pipe fills an empty tank to 1/2 of capacity in 3 hours and a second inlet pipe fills the same empty tank to 2/3 of capacity in 6 hours. How many hours will it take both pipes, pumping simultaneously at their respective constant rates, to fill the empty tank to capacity?

(A) 3.25
(B) 3.6
(C) 4.2
(D) 4.4
(E) 5.5

Kudos for a correct solution.


Total capacity = C

Rate of 1 = C/6
Rate of 2 = C/9
Combined rate = 5C/18
Time = 18/5 = 3.6 (B)
_________________

If you like my post, Pl. do not hesitate to press kudos!!!!

Q51 on GMAT - PM me if you need any help with GMAT QUANTS!!!

SVP
SVP
User avatar
P
Joined: 08 Jul 2010
Posts: 2298
Location: India
GMAT: INSIGHT
WE: Education (Education)
Reviews Badge
Re: Pumping alone at their respective constant rates, one inlet pipe fills  [#permalink]

Show Tags

New post 17 Oct 2015, 07:42
Bunuel wrote:
Pumping alone at their respective constant rates, one inlet pipe fills an empty tank to 1/2 of capacity in 3 hours and a second inlet pipe fills the same empty tank to 2/3 of capacity in 6 hours. How many hours will it take both pipes, pumping simultaneously at their respective constant rates, to fill the empty tank to capacity?

(A) 3.25
(B) 3.6
(C) 4.2
(D) 4.4
(E) 5.5

Kudos for a correct solution.


Time taken by First tank Fill 1/2 the tank = 3 hours
i.e. Time taken by First tank to Fill 1 complete the tank = 6 hours

Time taken by Second tank Fill 2/3 the tank = 6 hours
i.e. Time taken by First tank to Fill 1 complete the tank = (3/2)*6 = 9 hours

in 1 Hour, Both tanks together Fill the tank = (1/6)+(1/9) = 5/18 tank
i.e. Time taken by Both tank to Fill 1 complete the tank = 18/5 hours = 3.6 hours

Answer: option B
_________________

Prosper!!!
GMATinsight
Bhoopendra Singh and Dr.Sushma Jha
e-mail: info@GMATinsight.com I Call us : +91-9999687183 / 9891333772
Online One-on-One Skype based classes and Classroom Coaching in South and West Delhi
http://www.GMATinsight.com/testimonials.html

22 ONLINE FREE (FULL LENGTH) GMAT CAT (PRACTICE TESTS) LINK COLLECTION

Retired Moderator
avatar
Joined: 29 Oct 2013
Posts: 271
Concentration: Finance
GPA: 3.7
WE: Corporate Finance (Retail Banking)
GMAT ToolKit User
Re: Pumping alone at their respective constant rates, one inlet pipe fills  [#permalink]

Show Tags

New post 11 Dec 2015, 10:17
1
let c be tank capacity.
Time taken by First pipe to fill 1/2 the tank = 3 hours. So work done in 1 hr= c*{1/(2*3)}= c/6

Time taken by Second pipe to Fill 2/3 the tank = 6 hours. So work done in 1hr= c*{2/(3*6)}=c/9

in 1 Hour, Both tanks together Fill the tank = (1c/6)+(c1/9) = 5c/18
i.e. Time taken by Both tank to Fill 1 complete the tank = 18/5 hours = 3.6 hours

Answer: option B
_________________

Please contact me for super inexpensive quality private tutoring

My journey V46 and 750 -> http://gmatclub.com/forum/my-journey-to-46-on-verbal-750overall-171722.html#p1367876

Manager
Manager
avatar
B
Joined: 13 Feb 2011
Posts: 92
GMAT ToolKit User
Pumping alone at their respective constant rates, one inlet pipe fills  [#permalink]

Show Tags

New post 17 Feb 2016, 15:50
Bunuel wrote:
Pumping alone at their respective constant rates, one inlet pipe fills an empty tank to 1/2 of capacity in 3 hours and a second inlet pipe fills the same empty tank to 2/3 of capacity in 6 hours. How many hours will it take both pipes, pumping simultaneously at their respective constant rates, to fill the empty tank to capacity?

(A) 3.25
(B) 3.6
(C) 4.2
(D) 4.4
(E) 5.5

Kudos for a correct solution.

An alternative, logical approach with minimal calculations and no variables: First pipe fills full capacity in 6 hours, therefore fills approx. 16.6% in 1 hr. Second pipe fills 2/3 in 6 hours, therefore fills approx. 11% in 1 hr. Combined, they'd fill 27.6% per hr and would need just a bit less than 4 hours to fill the tank completely. Only choice in that range is B.
Intern
Intern
User avatar
Joined: 30 Aug 2015
Posts: 31
Concentration: Marketing, Finance
WE: Brand Management (Manufacturing)
Re: Pumping alone at their respective constant rates, one inlet pipe fills  [#permalink]

Show Tags

New post 17 Feb 2016, 16:47
2
Time taken by First tank Fill 1/2 the tank = 3 hours
i.e. Time taken by First tank to Fill 1 complete the tank = 6 hours

Time taken by Second tank Fill 2/3 the tank = 6 hours
i.e. Time taken by First tank to Fill 1 complete the tank = (3/2)*6 = 9 hours

in 1 Hour, Both tanks together Fill the tank = (1/6)+(1/9) = 5/18 tank
i.e. Time taken by Both tank to Fill 1 complete the tank = 18/5 hours = 3.6 hours

correct answer .... b
_________________

Please award kudos if you like my explanation.
Thanks :)

Board of Directors
User avatar
P
Status: QA & VA Forum Moderator
Joined: 11 Jun 2011
Posts: 4011
Location: India
GPA: 3.5
WE: Business Development (Commercial Banking)
GMAT ToolKit User Premium Member
Re: Pumping alone at their respective constant rates, one inlet pipe fills  [#permalink]

Show Tags

New post 05 Jun 2017, 11:13
Bunuel wrote:
Pumping alone at their respective constant rates, one inlet pipe fills an empty tank to 1/2 of capacity in 3 hours and a second inlet pipe fills the same empty tank to 2/3 of capacity in 6 hours. How many hours will it take both pipes, pumping simultaneously at their respective constant rates, to fill the empty tank to capacity?

(A) 3.25
(B) 3.6
(C) 4.2
(D) 4.4
(E) 5.5


The inlet pipe fills the empty tank to full capacity in 6 hours
The outlet pipe fills the empty tank to full capacity in 9 hours

Let, the capacity of the tank be 18 units..

So, efficiency of the inlet pipe is 3 inits/hr
And, efficiency of the outlet pipe is 2 inits/hr

Combined efficiency of both the pipes is 5 units/hr

Thus, time required by both the pipes to fill the tank will be \(\frac{18}{5}\) = 3.6 Hours

Hence, answer will be (B) 3.6 hours...
_________________

Thanks and Regards

Abhishek....

PLEASE FOLLOW THE RULES FOR POSTING IN QA AND VA FORUM AND USE SEARCH FUNCTION BEFORE POSTING NEW QUESTIONS

How to use Search Function in GMAT Club | Rules for Posting in QA forum | Writing Mathematical Formulas |Rules for Posting in VA forum | Request Expert's Reply ( VA Forum Only )

Target Test Prep Representative
User avatar
G
Status: Head GMAT Instructor
Affiliations: Target Test Prep
Joined: 04 Mar 2011
Posts: 2835
Re: Pumping alone at their respective constant rates, one inlet pipe fills  [#permalink]

Show Tags

New post 18 Aug 2018, 20:12
Bunuel wrote:
Pumping alone at their respective constant rates, one inlet pipe fills an empty tank to 1/2 of capacity in 3 hours and a second inlet pipe fills the same empty tank to 2/3 of capacity in 6 hours. How many hours will it take both pipes, pumping simultaneously at their respective constant rates, to fill the empty tank to capacity?

(A) 3.25
(B) 3.6
(C) 4.2
(D) 4.4
(E) 5.5


We are given that the first inlet pipe fills an empty tank to 1/2 capacity in 3 hours. Since rate = work/time, the rate of the first inlet pipe is (1/2)/3 = 1/6.

We are also given that the second inlet pipe fills the same empty tank to 2/3 capacity in 6 hours. Thus, the rate of the second inlet pipe is (2/3)/6 = 1/9.

We need to determine how many hours it will take both pipes, pumping simultaneously at their respective constant rates, to fill the empty tank to capacity.

If we let t = the time in hours the two inlet pipes are working together, then the work of the first inlet pipe = (1/6)t and the work of the second inlet pipe = (1/9)t.

Since the tank is filled, we can set total work to 1 and create the following equation:

(1/6)t + (1/9)t = 1

Multiplying the entire equation by 18, we obtain:

3t + 2t = 18

5t = 18

t = 18/5 = 3.6

Answer: B
_________________

Jeffery Miller
Head of GMAT Instruction

GMAT Quant Self-Study Course
500+ lessons 3000+ practice problems 800+ HD solutions

Re: Pumping alone at their respective constant rates, one inlet pipe fills &nbs [#permalink] 18 Aug 2018, 20:12
Display posts from previous: Sort by

Pumping alone at their respective constant rates, one inlet pipe fills

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  

Events & Promotions

PREV
NEXT


GMAT Club MBA Forum Home| About| Terms and Conditions and Privacy Policy| GMAT Club Rules| Contact| Sitemap

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne

Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.