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

It is currently 15 Dec 2018, 09:25

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
Events & Promotions in December
PrevNext
SuMoTuWeThFrSa
2526272829301
2345678
9101112131415
16171819202122
23242526272829
303112345
Open Detailed Calendar
  • $450 Tuition Credit & Official CAT Packs FREE

     December 15, 2018

     December 15, 2018

     10:00 PM PST

     11:00 PM PST

    Get the complete Official GMAT Exam Pack collection worth $100 with the 3 Month Pack ($299)
  • FREE Quant Workshop by e-GMAT!

     December 16, 2018

     December 16, 2018

     07:00 AM PST

     09:00 AM PST

    Get personalized insights on how to achieve your Target Quant Score.

A, B and C work on a task. To complete the task alone, B

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

Hide Tags

Director
Director
User avatar
S
Joined: 17 Dec 2012
Posts: 632
Location: India
A, B and C work on a task. To complete the task alone, B  [#permalink]

Show Tags

New post 26 Jun 2014, 20:03
3
13
00:00
A
B
C
D
E

Difficulty:

  95% (hard)

Question Stats:

47% (03:27) correct 53% (03:05) wrong based on 121 sessions

HideShow timer Statistics

A, B and C work on a task. To complete the task alone, B takes twice the time that A would take to complete the task alone and 2/3rd the time that C would take to complete the task alone. If B actually worked for half the number of days that A worked and 3/2 times the number of days that C worked, what proportion of the total work was completed by B?

A. 1/3
B. 2/9
C. 9/49
D. 7/19
E. 1/6

_________________

Srinivasan Vaidyaraman
Sravna Holistic Solutions
http://www.sravnatestprep.com

Holistic and Systematic Approach

Senior Manager
Senior Manager
User avatar
Joined: 13 Jun 2013
Posts: 275
Premium Member
Re: A, B and C work on a task. To complete the task alone, B  [#permalink]

Show Tags

New post 27 Jun 2014, 01:07
SravnaTestPrep wrote:
A, B and C work on a task. To complete the task alone, B takes twice the time that A would take to complete the task alone and 2/3rd the time that C would take to complete the task alone. If B actually worked for half the number of days that A worked and 3/2 times the number of days that C worked, what proportion of the total work was completed by B?

A. 1/3
B. 2/9
C. 9/49
D. 7/19
E. 1/6


efficiency of A in doing the work = x
efficiency of B in doing the work = x/2
efficiency of C in doing the work = x/3

now suppose A work for 6 days, then b will work for 3 days and C will work for 2 days

proportion of work completed by B = 3(x/2) / (6x+3(x/2)+2(x/3)
= 9/49
Current Student
avatar
B
Joined: 23 May 2013
Posts: 188
Location: United States
Concentration: Technology, Healthcare
Schools: Stanford '19 (M)
GMAT 1: 760 Q49 V45
GPA: 3.5
GMAT ToolKit User
A, B and C work on a task. To complete the task alone, B  [#permalink]

Show Tags

New post 29 Oct 2014, 11:46
1
SravnaTestPrep wrote:
A, B and C work on a task. To complete the task alone, B takes twice the time that A would take to complete the task alone and 2/3rd the time that C would take to complete the task alone. If B actually worked for half the number of days that A worked and 3/2 times the number of days that C worked, what proportion of the total work was completed by B?

A. 1/3
B. 2/9
C. 9/49
D. 7/19
E. 1/6


This is a variable question, so we can just assign arbitrary values to simplify the problem greatly.

To complete the task alone, B takes twice the time that A would take to complete the task alone and 2/3rd the time that C would take to complete the task alone. If it takes 1 day for A to do the project, then it takes 2 days for B and 3 days for C.

If B actually worked for half the number of days that A worked and 3/2 times the number of days that C worked, what proportion of the total work was completed by B?

Let's say A worked 1 day. Then A completed 1 project. B worked for 1/2 a day, and since it takes him 2 days, he completed \(\frac{1/2}{2} = \frac{1}{4}\) of a project. C then worked for 1/3 of a day, and completed \(\frac{1/3}{3} = \frac{1}{9}\) of a project.

Then to find the proportion, we take \(\frac{1/4}{1+1/4+1/9} = \frac{9}{49}\).

Answer: C
Intern
Intern
User avatar
Joined: 04 Jul 2014
Posts: 46
Schools: Smeal" 20
Re: A, B and C work on a task. To complete the task alone, B  [#permalink]

Show Tags

New post 30 Oct 2014, 19:56
SravnaTestPrep wrote:
A, B and C work on a task. To complete the task alone, B takes twice the time that A would take to complete the task alone and 2/3rd the time that C would take to complete the task alone. If B actually worked for half the number of days that A worked and 3/2 times the number of days that C worked, what proportion of the total work was completed by B?

A. 1/3
B. 2/9
C. 9/49
D. 7/19
E. 1/6


The first thing to notice is that A is faster than B and B is faster than C.

Since work is proportional to time, in 1 day lets say if A does 2 works, B does 1 work and C does 2/3rd of a work.

If A works for 2 days, B works for 1 day and C works for only 2/3 of the day.

Therefore total work done = (2*2) + (1*1) + (2/3*2/3) = 49/9

Proportion of work done by B = (1*1) / (49/9) = 9/49

Hence Answer C.
--------------------------------

Kudos please, if this post helps.
Manager
Manager
avatar
B
Joined: 04 Oct 2017
Posts: 72
Re: A, B and C work on a task. To complete the task alone, B  [#permalink]

Show Tags

New post 23 Feb 2018, 19:07
Vetrik wrote:
SravnaTestPrep wrote:
A, B and C work on a task. To complete the task alone, B takes twice the time that A would take to complete the task alone and 2/3rd the time that C would take to complete the task alone. If B actually worked for half the number of days that A worked and 3/2 times the number of days that C worked, what proportion of the total work was completed by B?

A. 1/3
B. 2/9
C. 9/49
D. 7/19
E. 1/6


The first thing to notice is that A is faster than B and B is faster than C.

Since work is proportional to time, in 1 day lets say if A does 2 works, B does 1 work and C does 2/3rd of a work.

If A works for 2 days, B works for 1 day and C works for only 2/3 of the day.

Therefore total work done = (2*2) + (1*1) + (2/3*2/3) = 49/9

Proportion of work done by B = (1*1) / (49/9) = 9/49

Hence Answer C.
--------------------------------

Kudos please, if this post helps.


How did you arrive at ...C does 2/3 of the work??? I did not understand ...B works for 3/2 times the number of days C worked???
Intern
Intern
avatar
Joined: 23 Feb 2018
Posts: 1
Re: A, B and C work on a task. To complete the task alone, B  [#permalink]

Show Tags

New post 23 Feb 2018, 20:23
Kezia9 wrote:
Vetrik wrote:
SravnaTestPrep wrote:
A, B and C work on a task. To complete the task alone, B takes twice the time that A would take to complete the task alone and 2/3rd the time that C would take to complete the task alone. If B actually worked for half the number of days that A worked and 3/2 times the number of days that C worked, what proportion of the total work was completed by B?

A. 1/3
B. 2/9
C. 9/49
D. 7/19
E. 1/6


The first thing to notice is that A is faster than B and B is faster than C.

Since work is proportional to time, in 1 day lets say if A does 2 works, B does 1 work and C does 2/3rd of a work.

If A works for 2 days, B works for 1 day and C works for only 2/3 of the day.

Therefore total work done = (2*2) + (1*1) + (2/3*2/3) = 49/9

Proportion of work done by B = (1*1) / (49/9) = 9/49

Hence Answer C.
--------------------------------

Kudos please, if this post helps.


How did you arrive at ...C does 2/3 of the work??? I did not understand ...B works for 3/2 times the number of days C worked???


We can use ratios to understand it better-
Given that B worked half the number of days that A worked,implies: B= (1/2)*A
Or, A/B = 2/1 (Here it means that when A works for 2 days,B works for a day).

Now, relating B and C: B works 3/2 times C.
Or, B= (3/2)*C
B/C = 3/2.
This can be rewritten as : B/C = 1/(2/3) {In other words, when B works for a day, C works for 2/3 day}



Sent from my iPhone using GMAT Club Forum mobile app
GMAT Club Bot
Re: A, B and C work on a task. To complete the task alone, B &nbs [#permalink] 23 Feb 2018, 20:23
Display posts from previous: Sort by

A, B and C work on a task. To complete the task alone, B

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


Copyright

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®.