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

 It is currently 22 Jan 2019, 19:23

### 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 January
PrevNext
SuMoTuWeThFrSa
303112345
6789101112
13141516171819
20212223242526
272829303112
Open Detailed Calendar
• ### The winners of the GMAT game show

January 22, 2019

January 22, 2019

10:00 PM PST

11:00 PM PST

In case you didn’t notice, we recently held the 1st ever GMAT game show and it was awesome! See who won a full GMAT course, and register to the next one.
• ### Key Strategies to Master GMAT SC

January 26, 2019

January 26, 2019

07:00 AM PST

09:00 AM PST

Attend this webinar to learn how to leverage Meaning and Logic to solve the most challenging Sentence Correction Questions.

# Work Problem, How long does it take for one worker do it by himself?

Author Message
Intern
Joined: 08 Jan 2018
Posts: 1
Work Problem, How long does it take for one worker do it by himself?  [#permalink]

### Show Tags

08 Jan 2018, 11:14
00:00

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions

### HideShow timer Statistics

Worker A takes 8 hours to do a Job, Worker B & C takes 6 hours do that same job and Worker A and C takes 4 Hours to do that same job.

How long does it take for Worker B to do it by himself?

Bit confused on this one for myself

--== Message from the GMAT Club Team ==--

THERE IS LIKELY A BETTER DISCUSSION OF THIS EXACT QUESTION.
This discussion does not meet community quality standards. It has been retired.

If you would like to discuss this question please re-post it in the respective forum. Thank you!

To review the GMAT Club's Forums Posting Guidelines, please follow these links: Quantitative | Verbal Please note - we may remove posts that do not follow our posting guidelines. Thank you.
Intern
Joined: 08 Dec 2017
Posts: 16
Re: Work Problem, How long does it take for one worker do it by himself?  [#permalink]

### Show Tags

08 Jan 2018, 16:32
A does 1/8 of the job per hour. A and c together to 1/4 of the job per hour.
C must also do 1/8 of the job per hour.
B and c do 1/6 of the job per hour and c does 1:8.
B must do the rest. 1/6-1/8=1/24.
B does 1/24 of the job per hour so it takes him 24 hours.
Manager
Joined: 23 Oct 2017
Posts: 64
Re: Work Problem, How long does it take for one worker do it by himself?  [#permalink]

### Show Tags

08 Jan 2018, 22:04
chaosfirestorm wrote:
Worker A takes 8 hours to do a Job, Worker B & C takes 6 hours do that same job and Worker A and C takes 4 Hours to do that same job.

How long does it take for Worker B to do it by himself?

Bit confused on this one for myself

--------------

Lets convert the problem statement into equations:
Worker A takes 8 hours to do a Job, => a= 8 (a is the time required for worker A to complete the job)
Worker B & C takes 6 hours do that same job
=> 1/b + 1/c = 6 --(1)
(where b & c are the hours required for worker b & C to complete the job if done individually)
and Worker A and C takes 4 Hours to do that same job
=> 1/a + 1/c = 1/4
since a=8
1/c = 1/8

Substituting the value of c in (1) - we get 1/b = 1/24
Thus, it takes 24 hours for Worker B to do it by himself
Intern
Joined: 06 Jan 2018
Posts: 4
Re: Work Problem, How long does it take for one worker do it by himself?  [#permalink]

### Show Tags

08 Jan 2018, 22:27
It takes worker A and C 4 hours to do the job, half the time it takes A. So A and C work at equal speed. Therefore we van say it takes B and A 6 hours. A completes 3/4 of the job in 6 hours, so B does 1/4 of the job in 6 hours. So it takes her 24 hours to do the job on her own.

Sent from my U FEEL PRIME using GMAT Club Forum mobile app
Intern
Joined: 01 Jun 2015
Posts: 41
Location: India
Re: Work Problem, How long does it take for one worker do it by himself?  [#permalink]

### Show Tags

09 Jan 2018, 08:54
1
A * 8 = LCM(8,6,4)

(B+C)*6 = LCM(8,6,4)

(A+C)*4 = LCM(8,6,4)

A = 3
B+C = 4
A + C = 6

solving , B=1

B*1 = 24

Hence 24 hours
Math Expert
Joined: 02 Sep 2009
Posts: 52390
Re: Work Problem, How long does it take for one worker do it by himself?  [#permalink]

### Show Tags

13 Jan 2018, 08:56
chaosfirestorm wrote:
Worker A takes 8 hours to do a Job, Worker B & C takes 6 hours do that same job and Worker A and C takes 4 Hours to do that same job.

How long does it take for Worker B to do it by himself?

Bit confused on this one for myself

--== Message from the GMAT Club Team ==--

THERE IS LIKELY A BETTER DISCUSSION OF THIS EXACT QUESTION.
This discussion does not meet community quality standards. It has been retired.

If you would like to discuss this question please re-post it in the respective forum. Thank you!

To review the GMAT Club's Forums Posting Guidelines, please follow these links: Quantitative | Verbal Please note - we may remove posts that do not follow our posting guidelines. Thank you.

_________________
Re: Work Problem, How long does it take for one worker do it by himself? &nbs [#permalink] 13 Jan 2018, 08:56
Display posts from previous: Sort by