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

It is currently 11 Dec 2019, 15:29

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

A is 30% more efficient than B. How much time will they take to

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

Hide Tags

Find Similar Topics 
Manager
Manager
avatar
G
Joined: 13 Aug 2018
Posts: 55
A is 30% more efficient than B. How much time will they take to  [#permalink]

Show Tags

New post 25 May 2019, 04:41
3
00:00
A
B
C
D
E

Difficulty:

  55% (hard)

Question Stats:

61% (02:06) correct 39% (01:57) wrong based on 62 sessions

HideShow timer Statistics

A is 30% more efficient than B. How much time will they take to complete a job by working together, which A alone could have done in 23 days?

A. 10 days
B. 13 days
C. 15 days
D. 17 days
E. 19 days
NUS School Moderator
avatar
V
Joined: 18 Jul 2018
Posts: 1026
Location: India
Concentration: Finance, Marketing
WE: Engineering (Energy and Utilities)
Reviews Badge CAT Tests
Re: A is 30% more efficient than B. How much time will they take to  [#permalink]

Show Tags

New post 25 May 2019, 07:30
1
A takes 23 days to finish.
As the Efficiency of B is 1.3 times of A, then B takes 1.3*23 days.

1/A+1/B = 1/X
1/23+10/13*23 = (10+13)/13*23 = 1/X

X = (13*23)/23 = 13 days.

B is the answer.
Director
Director
User avatar
V
Joined: 27 May 2012
Posts: 947
Re: A is 30% more efficient than B. How much time will they take to  [#permalink]

Show Tags

New post 26 May 2019, 11:23
Chethan92 wrote:
A takes 23 days to finish.
As the Efficiency of B is 1.3 times of A, then B takes 1.3*23 days.

1/A+1/B = 1/X
1/23+10/13*23 = (10+13)/13*23 = 1/X

X = (13*23)/23 = 13 days.

B is the answer.


Hi Chethan92,
Please note A is 30% more efficient than B and not the other way round.
Also when Something is more efficient it takes lesser time NOT more.

You have taken B to be more efficient at the same time, B is taking more time??
_________________
- Stne
NUS School Moderator
avatar
V
Joined: 18 Jul 2018
Posts: 1026
Location: India
Concentration: Finance, Marketing
WE: Engineering (Energy and Utilities)
Reviews Badge CAT Tests
Re: A is 30% more efficient than B. How much time will they take to  [#permalink]

Show Tags

New post 26 May 2019, 11:27
stne wrote:
Chethan92 wrote:
A takes 23 days to finish.
As the Efficiency of B is 1.3 times of A, then B takes 1.3*23 days.

1/A+1/B = 1/X
1/23+10/13*23 = (10+13)/13*23 = 1/X

X = (13*23)/23 = 13 days.

B is the answer.


Hi Chethan92,
Please note A is 30% more efficient than B and not the other way round.
Also when Something is more efficient it takes lesser time NOT more.

You have taken B to be more efficient at the same time, B is taking more time??


Wording problem. :) And yes, I KNOW THAT THE PERSON WHO IS MORE EFFICIENT TAKES LESS TIME.
Director
Director
User avatar
V
Joined: 27 May 2012
Posts: 947
Re: A is 30% more efficient than B. How much time will they take to  [#permalink]

Show Tags

New post 26 May 2019, 11:30
Chethan92 wrote:
stne wrote:
Chethan92 wrote:
A takes 23 days to finish.
As the Efficiency of B is 1.3 times of A, then B takes 1.3*23 days.

1/A+1/B = 1/X
1/23+10/13*23 = (10+13)/13*23 = 1/X

X = (13*23)/23 = 13 days.

B is the answer.


Hi Chethan92,
Please note A is 30% more efficient than B and not the other way round.
Also when Something is more efficient it takes lesser time NOT more.

You have taken B to be more efficient at the same time, B is taking more time??


Wording problem. :) And yes, I KNOW THAT THE PERSON WHO IS MORE EFFICIENT TAKES LESS TIME.


But then why is B taking more time , in your equation?
_________________
- Stne
NUS School Moderator
avatar
V
Joined: 18 Jul 2018
Posts: 1026
Location: India
Concentration: Finance, Marketing
WE: Engineering (Energy and Utilities)
Reviews Badge CAT Tests
Re: A is 30% more efficient than B. How much time will they take to  [#permalink]

Show Tags

New post 26 May 2019, 11:32
A is more efficient. So, B has to take more time?

Posted from my mobile device
Director
Director
User avatar
V
Joined: 27 May 2012
Posts: 947
Re: A is 30% more efficient than B. How much time will they take to  [#permalink]

Show Tags

New post 26 May 2019, 11:35
Chethan92 wrote:
A is more efficient. So, B has to take more time?

Posted from my mobile device



I was talking about YOUR EQUATION in which you have taken B to be more efficient than A.
_________________
- Stne
NUS School Moderator
avatar
V
Joined: 18 Jul 2018
Posts: 1026
Location: India
Concentration: Finance, Marketing
WE: Engineering (Energy and Utilities)
Reviews Badge CAT Tests
Re: A is 30% more efficient than B. How much time will they take to  [#permalink]

Show Tags

New post 26 May 2019, 11:37
As I SAID BEFORE, I should have wrote it as time taken by B is 1.3times of A.

Posted from my mobile device
Senior Manager
Senior Manager
User avatar
P
Joined: 03 Mar 2017
Posts: 373
Reviews Badge CAT Tests
Re: A is 30% more efficient than B. How much time will they take to  [#permalink]

Show Tags

New post 27 May 2019, 18:25
Chethan92 wrote:
A takes 23 days to finish.
As the Efficiency of B is 1.3 times of A, then B takes 1.3*23 days.

1/A+1/B = 1/X
1/23+10/13*23 = (10+13)/13*23 = 1/X

X = (13*23)/23 = 13 days.

B is the answer.



The problem with your solution is the line highlighted.

Its not B that is efficient . You should correct it and write "As the Efficiency of A is 1.3 times of B, B takes 1.3*23 days.

This will clear your and others concepts as well.

No offenses mate!!
_________________
--------------------------------------------------------------------------------------------------------------------------
All the Gods, All the Heavens, and All the Hells lie within you.
ISB School Moderator
User avatar
G
Joined: 08 Dec 2013
Posts: 619
Location: India
Concentration: Nonprofit, Sustainability
Schools: ISB '21
GMAT 1: 630 Q47 V30
WE: Operations (Non-Profit and Government)
Reviews Badge CAT Tests
Re: A is 30% more efficient than B. How much time will they take to  [#permalink]

Show Tags

New post 27 May 2019, 18:33
1
jackfr2 wrote:
A is 30% more efficient than B. How much time will they take to complete a job by working together, which A alone could have done in 23 days?

A. 10 days
B. 13 days
C. 15 days
D. 17 days
E. 19 days


Let efficiency A= 130 and B=100, we have to find x
A23 = (A+B)x
130 * 23 = 230 * x
x=13 B
GMAT Club Bot
Re: A is 30% more efficient than B. How much time will they take to   [#permalink] 27 May 2019, 18:33
Display posts from previous: Sort by

A is 30% more efficient than B. How much time will they take to

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





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