Last visit was: 24 Apr 2026, 10:33 It is currently 24 Apr 2026, 10:33
Home
Messages
Tests
Schools
Events
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.
Go to My Error Log Learn more
Close
Request Expert Reply
Confirm Cancel
Back to Forum
Create Topic
User avatar
atsdabhay
User avatar
Joined: 26 Sep 2020
Last visit: 01 Feb 2021
Posts: 7
Own Kudos:
5
 [4]
Given Kudos: 4
Posts: 7
Kudos: 5
 [4]
6 men can finish a piece of work in 2 hours. How long will 9 men take 03 Oct 2020, 03:40
Kudos
Add Kudos
4
Bookmarks
Bookmark this Post
00:00
Start Timer
Pause Timer
Resume Timer
Show Answer
Hide
Show
History
D
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!

Difficulty:

35% (medium)

Question Stats:

71% (01:35) correct 29% (01:59) wrong based on 152 sessions

History

Date
Time
Result
Not Attempted Yet
6 men can finish a piece of work in 2 hours. How long will 9 men take to finish the work if they can work only at 4/5th the capacity of the initial workers?

A. 5/12
B. 16/15
C. 3/2
D. 5/3
E. 2
ShowHide Answer
Official Answer
D
User avatar
CrackverbalGMAT
User avatar
Major Poster
Joined: 03 Oct 2013
Last visit: 24 Apr 2026
Posts: 4,846
Own Kudos:
9,182
 [2]
Given Kudos: 226
Affiliations: CrackVerbal
Location: India
Expert
Expert reply
Posts: 4,846
Kudos: 9,182
 [2]
6 men can finish a piece of work in 2 hours. How long will 9 men take 03 Oct 2020, 03:56
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
6 workers take 2 hours to finish the work.

Therefore the time taken by 1 worker = 12 hours

The new worker works at 4/5 capacity of the initial workers.

Therefore the time taken by 1 worker (new) = (5/4) * 12 = 15hours

Amount of work done by 1 worker in 1 hour = 1/15

Therefore the work done by 9 workers in 1 hour = 9/15 = 3/5

Therefore the time taken (flipping the numerator and denominator = 5/3


Option D

Arun Kumar
User avatar
atsdabhay
User avatar
Joined: 26 Sep 2020
Last visit: 01 Feb 2021
Posts: 7
Own Kudos:
5
 [1]
Given Kudos: 4
Posts: 7
Kudos: 5
 [1]
6 men can finish a piece of work in 2 hours. How long will 9 men take 03 Oct 2020, 04:13
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
CrackVerbalGMAT
6 workers take 2 hours to finish the work.

Therefore the time taken by 1 worker = 12 hours

The new worker works at 4/5 capacity of the initial workers.

Therefore the time taken by 1 worker (new) = (5/4) * 12 = 15hours

Amount of work done by 1 worker in 1 hour = 1/15

Therefore the work done by 9 workers in 1 hour = 9/15 = 3/5

Therefore the time taken (flipping the numerator and denominator = 5/3


Option D

Arun Kumar
Show more



hello, i still couldn't understand the problem. why are we multiplying time taken by 5/4 and not 4/5. can you please elaborate?
User avatar
CrackverbalGMAT
User avatar
Major Poster
Joined: 03 Oct 2013
Last visit: 24 Apr 2026
Posts: 4,846
Own Kudos:
9,182
 [1]
Given Kudos: 226
Affiliations: CrackVerbal
Location: India
Expert
Expert reply
Posts: 4,846
Kudos: 9,182
 [1]
6 men can finish a piece of work in 2 hours. How long will 9 men take 03 Oct 2020, 04:21
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
atsdabhay
CrackVerbalGMAT
6 workers take 2 hours to finish the work.

Therefore the time taken by 1 worker = 12 hours

The new worker works at 4/5 capacity of the initial workers.

Therefore the time taken by 1 worker (new) = (5/4) * 12 = 15hours

Amount of work done by 1 worker in 1 hour = 1/15

Therefore the work done by 9 workers in 1 hour = 9/15 = 3/5

Therefore the time taken (flipping the numerator and denominator = 5/3


Option D

Arun Kumar



hello, i still couldn't understand the problem. why are we multiplying time taken by 5/4 and not 4/5. can you please elaborate?
Show more


when you work at 4/5 th capacity you will take more time than normal.

This can be explained in terms of efficiency. The more efficient you are, the lesser time you take. So efficiency is inversely proportional to time.


Now E (New) = 4/5 (E (old)

So E (New) / E(old) = 4/5

Therefore Time (New) / Time (old) = 5/4

Time (new) = 5/4 Time (old) = 5/4 * 12 = 15

Hope this helps

Arun Kumar
User avatar
atsdabhay
User avatar
Joined: 26 Sep 2020
Last visit: 01 Feb 2021
Posts: 7
Own Kudos:
5
Given Kudos: 4
Posts: 7
Kudos: 5
6 men can finish a piece of work in 2 hours. How long will 9 men take 03 Oct 2020, 04:30
Kudos
Add Kudos
Bookmarks
Bookmark this Post
CrackVerbalGMAT
atsdabhay
CrackVerbalGMAT
6 workers take 2 hours to finish the work.

Therefore the time taken by 1 worker = 12 hours

The new worker works at 4/5 capacity of the initial workers.

Therefore the time taken by 1 worker (new) = (5/4) * 12 = 15hours

Amount of work done by 1 worker in 1 hour = 1/15

Therefore the work done by 9 workers in 1 hour = 9/15 = 3/5

Therefore the time taken (flipping the numerator and denominator = 5/3


Option D

Arun Kumar



hello, i still couldn't understand the problem. why are we multiplying time taken by 5/4 and not 4/5. can you please elaborate?


when you work at 4/5 th capacity you will take more time than normal.

This can be explained in terms of efficiency. The more efficient you are, the lesser time you take. So efficiency is inversely proportional to time.


Now E (New) = 4/5 (E (old)

So E (New) / E(old) = 4/5

Therefore Time (New) / Time (old) = 5/4

Time (new) = 5/4 Time (old) = 5/4 * 12 = 15

Hope this helps

Arun Kumar
Show more


is it similar to the concept saying if 5 units of work is done in 4 hours then time taken to complete 5 work = 4/5 hours?
User avatar
Abhishek009
User avatar
Board of Directors
Joined: 11 Jun 2011
Last visit: 17 Dec 2025
Posts: 5,903
Own Kudos:
5,454
 [1]
Given Kudos: 463
Status:QA & VA Forum Moderator
Location: India
GPA: 3.5
WE:Business Development (Commercial Banking)
Posts: 5,903
Kudos: 5,454
 [1]
6 men can finish a piece of work in 2 hours. How long will 9 men take 03 Oct 2020, 07:08
Kudos
Add Kudos
1
Bookmarks
Bookmark this Post
atsdabhay
6 men can finish a piece of work in 2 hours. How long will 9 men take to finish the work if they can work only at 4/5th the capacity of the initial workers?

A. 5/12
B. 16/15
C. 3/2
D. 5/3
E. 2
Show more
\(\frac{6*2}{9}*\frac{5}{4}=\frac{5}{3}\), Answer must be (D)
User avatar
MathRevolution
User avatar
Math Revolution GMAT Instructor
Joined: 16 Aug 2015
Last visit: 27 Sep 2022
Posts: 10,063
Own Kudos:
20,000
 [4]
Given Kudos: 4
GMAT 1: 760 Q51 V42
GPA: 3.82
Expert
Expert reply
GMAT 1: 760 Q51 V42
Posts: 10,063
Kudos: 20,000
 [4]
6 men can finish a piece of work in 2 hours. How long will 9 men take 03 Oct 2020, 08:13
1
Kudos
Add Kudos
3
Bookmarks
Bookmark this Post
\(\frac{(M_1 * H_1)}{ W_1} = \frac{(M_2 * H_2)}{ W_2}\)

=> \(\frac{(6 * 2) }{ 1} = \frac{9 * H_2}{\frac{5}{4}}\)

=> 5 * 6 * 2 = 4 * 9 * \(H_2\)

=> \(H_2\) = \(\frac{5}{3}\)

Answer D
User avatar
Basshead
User avatar
Joined: 09 Jan 2020
Last visit: 07 Feb 2024
Posts: 906
Own Kudos:
323
Given Kudos: 431
Location: United States
Posts: 906
Kudos: 323
6 men can finish a piece of work in 2 hours. How long will 9 men take 16 Oct 2020, 07:19
Kudos
Add Kudos
Bookmarks
Bookmark this Post
amount = rate * time.
Rate and time are inversely related. If John can complete a job in \(\frac{4}{5}\) hours, his rate is \(\frac{5}{4}\).

6 men can finish a piece of work in 2 hours. 1 man can finish a piece of work in 12 hours.

How long will 9 men take to finish the work if they can work only at 4/5th the capacity of the initial workers?

9 men rate = \(\frac{12 hours }{ 9 men}\)

\(\frac{12}{9}\)*\(\frac{5}{4}\) =\(\frac{5}{3}\)

Answer is D.
User avatar
ramlala
User avatar
Joined: 22 Aug 2020
Last visit: 13 Dec 2022
Posts: 467
Own Kudos:
384
Given Kudos: 30
Location: India
Concentration: International Business, Finance
Schools: IIMA PGPX'23 INSEAD Jan'23 intake Sloan (MIT) ISB HEC Said
GPA: 4
WE:Project Management (Energy)
Schools: IIMA PGPX'23 INSEAD Jan'23 intake Sloan (MIT) ISB HEC Said
Posts: 467
Kudos: 384
6 men can finish a piece of work in 2 hours. How long will 9 men take 16 Oct 2020, 09:36
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Total manhours = 6 x 2 = 12
New workers capacity = \(\frac{4}{5}\)

New manhours = 12 x \(\frac{5}{4}\)

Total time required = 12 x \(\frac{5}{4}\) x \(\frac{1}{9}\)

= \(\frac{5}{3}\)

Ans D
User avatar
bumpbot
User avatar
Non-Human User
Joined: 09 Sep 2013
Last visit: 04 Jan 2021
Posts: 38,973
Own Kudos:
1,117
Posts: 38,973
Kudos: 1,117
6 men can finish a piece of work in 2 hours. How long will 9 men take 06 Jul 2023, 12:37
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Automated notice from GMAT Club BumpBot:

A member just gave Kudos to this thread, showing it’s still useful. I’ve bumped it to the top so more people can benefit. Feel free to add your own questions or solutions.

This post was generated automatically.
Moderators:
Bunuel
Math Expert
109814 posts
Krunaal
Tuck School Moderator
853 posts