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.

Thank you for using the timer!
We noticed you are actually not timing your practice. Click the START button first next time you use the timer.
There are many benefits to timing your practice, including:

Al can complete a particular job in 8 hours. Boris can [#permalink]
11 Jul 2006, 20:20

1

This post received KUDOS

9

This post was BOOKMARKED

00:00

A

B

C

D

E

Difficulty:

55% (hard)

Question Stats:

68% (03:20) correct
32% (02:36) wrong based on 174 sessions

Al can complete a particular job in 8 hours. Boris can complete the same job in 5 hours. Cody can complete a second job, which requires twice as much work as the first, in 8 hours. If all three people work together on the larger job for 2 hours, how long, in hours, would it take Al, working alone, to finish the job?

Re: PS: Work Problem [#permalink]
11 Jul 2006, 20:43

1

This post received KUDOS

X & Y wrote:

Al can complete a particular job in 8 hours. Boris can complete the same job in 5 hours. Cody can complete a second job, which requires twice as much work as the first, in 8 hours. If all three people work together on the larger job for 2 hours, how long, in hours, would it take Al, working alone, to finish the job?

a. 0.8 b. 3.0 c. 6.8 d. 8.0 e. 8.8

all three people working together on the larger job for 2 hours=(1/16+1/10+1/8)*2=23/40
remaining part of the job is 17/40 Al's working rate is 1/16 hence
(17/40)/(1/16)=34/5 or 6.8 C it is _________________

Re: Al can complete a particular job in 8 hours. Boris can [#permalink]
05 May 2012, 06:38

I am stumped by this question.

Al's rate is 1 Job / 8 Hours Boris's rate is 1 Job/ 5 Hours Cody's rate is 2 Job /8 Hours

When the question states that the second job required "twice the amount of work as the first" how does one interpret this? In the above posts you have the the time doubled, ie, Al's rate is no longer 1/8 but 1/16 (so the time to complete the job was doubled). But I saw it more as his rate to complete the job stayed the same and the job grew by a multiple of 2, ie, (1/8)*time_Al=2 job The rate should be doubled in the numerator and the denominator.So Al's rate of 1 Job/8 Hour becomes (2*1 Job/2*8 Hour)=2 Job/16 Hour Very confused.

Re: Al can complete a particular job in 8 hours. Boris can [#permalink]
06 May 2012, 02:16

1

This post received KUDOS

Expert's post

alphabeta1234 wrote:

I am stumped by this question.

Al's rate is 1 Job / 8 Hours Boris's rate is 1 Job/ 5 Hours Cody's rate is 2 Job /8 Hours

When the question states that the second job required "twice the amount of work as the first" how does one interpret this? In the above posts you have the the time doubled, ie, Al's rate is no longer 1/8 but 1/16 (so the time to complete the job was doubled). But I saw it more as his rate to complete the job stayed the same and the job grew by a multiple of 2, ie, (1/8)*time_Al=2 job The rate should be doubled in the numerator and the denominator.So Al's rate of 1 Job/8 Hour becomes (2*1 Job/2*8 Hour)=2 Job/16 Hour Very confused.

Al can complete a particular job in 8 hours. Boris can complete the same job in 5 hours. Cody can complete a second job, which requires twice as much work as the first, in 8 hours. If all three people work together on the larger job for 2 hours, how long, in hours, would it take Al, working alone, to finish the job? A. 0.8 B. 3.0 C. 6.8 D. 8.0 E. 8.8

Al can complete a particular job in 8 hours, hence he can complete the second job which requires twice as much work as the first in 16 hours --> the rate of Al for this larger job is 1/16 job/hour;

Boris can complete a particular job in 5 hours, hence he can complete the second job which requires twice as much work as the first in 10 hours --> the rate of Boris for this larger job is 1/10 job/hour;

The rate of Cody for this larger job is 1/8 job/hour.

In 2 hours all three would complete 2*(1/16+1/10+1/8)=23/40 part of the larger job, so 17/40 part of it is left to be done.

Al can complete it in time=job/rate=(17/40)/(1/16)=34/5=6.8 hours.

Re: Al can complete a particular job in 8 hours. Boris can [#permalink]
07 May 2012, 17:39

Bunuel wrote:

alphabeta1234 wrote:

I am stumped by this question.

Al's rate is 1 Job / 8 Hours Boris's rate is 1 Job/ 5 Hours Cody's rate is 2 Job /8 Hours

When the question states that the second job required "twice the amount of work as the first" how does one interpret this? In the above posts you have the the time doubled, ie, Al's rate is no longer 1/8 but 1/16 (so the time to complete the job was doubled). But I saw it more as his rate to complete the job stayed the same and the job grew by a multiple of 2, ie, (1/8)*time_Al=2 job The rate should be doubled in the numerator and the denominator.So Al's rate of 1 Job/8 Hour becomes (2*1 Job/2*8 Hour)=2 Job/16 Hour Very confused.

Al can complete a particular job in 8 hours. Boris can complete the same job in 5 hours. Cody can complete a second job, which requires twice as much work as the first, in 8 hours. If all three people work together on the larger job for 2 hours, how long, in hours, would it take Al, working alone, to finish the job? A. 0.8 B. 3.0 C. 6.8 D. 8.0 E. 8.8

Al can complete a particular job in 8 hours, hence he can complete the second job which requires twice as much work as the first in 16 hours --> the rate of Al for this larger job is 1/16 job/hour;

Boris can complete a particular job in 5 hours, hence he can complete the second job which requires twice as much work as the first in 10 hours --> the rate of Boris for this larger job is 1/10 job/hour;

The rate of Cody for this larger job is 1/8 job/hour.

In 2 hours all three would complete 2*(1/16+1/10+1/8)=23/40 part of the larger job, so 17/40 part of it is left to be done.

Al can complete it in time=job/rate=(17/40)/(1/16)=34/5=6.8 hours.

Answer: C.

Hope it's clear.

I understand the solution, but i have to question the structure of the sentence "which requires twice as much work as the first". it is assumed that Al and Boris too takes twice the amount of time and that double time is not applicable solely to Cody.

Re: Al can complete a particular job in 8 hours. Boris can [#permalink]
08 May 2012, 00:09

Expert's post

jayaddula wrote:

Bunuel wrote:

alphabeta1234 wrote:

I am stumped by this question.

Al's rate is 1 Job / 8 Hours Boris's rate is 1 Job/ 5 Hours Cody's rate is 2 Job /8 Hours

When the question states that the second job required "twice the amount of work as the first" how does one interpret this? In the above posts you have the the time doubled, ie, Al's rate is no longer 1/8 but 1/16 (so the time to complete the job was doubled). But I saw it more as his rate to complete the job stayed the same and the job grew by a multiple of 2, ie, (1/8)*time_Al=2 job The rate should be doubled in the numerator and the denominator.So Al's rate of 1 Job/8 Hour becomes (2*1 Job/2*8 Hour)=2 Job/16 Hour Very confused.

Al can complete a particular job in 8 hours. Boris can complete the same job in 5 hours. Cody can complete a second job, which requires twice as much work as the first, in 8 hours. If all three people work together on the larger job for 2 hours, how long, in hours, would it take Al, working alone, to finish the job? A. 0.8 B. 3.0 C. 6.8 D. 8.0 E. 8.8

Al can complete a particular job in 8 hours, hence he can complete the second job which requires twice as much work as the first in 16 hours --> the rate of Al for this larger job is 1/16 job/hour;

Boris can complete a particular job in 5 hours, hence he can complete the second job which requires twice as much work as the first in 10 hours --> the rate of Boris for this larger job is 1/10 job/hour;

The rate of Cody for this larger job is 1/8 job/hour.

In 2 hours all three would complete 2*(1/16+1/10+1/8)=23/40 part of the larger job, so 17/40 part of it is left to be done.

Al can complete it in time=job/rate=(17/40)/(1/16)=34/5=6.8 hours.

Answer: C.

Hope it's clear.

I understand the solution, but i have to question the structure of the sentence "which requires twice as much work as the first". it is assumed that Al and Boris too takes twice the amount of time and that double time is not applicable solely to Cody.

Yes. We are told that "a second job, ... requires twice as much work as the first", so it's not only for Coby but for everyone. _________________

Re: Al can complete a particular job in 8 hours. Boris can [#permalink]
21 Sep 2012, 05:06

Al can complete a particular job in 8 hours. Boris can complete the same job in 5 hours. Cody can complete a second job, which requires twice as much work as the first, in 8 hours. If all three people work together on the larger job for 2 hours, how long, in hours, would it take Al, working alone, to finish the job?

Bunuel ,question stem does not mention to find time for Al to complete remaining job. I misunderstood the question and calculated time for Al to finish the whole job.

Re: Al can complete a particular job in 8 hours. Boris can [#permalink]
21 Sep 2012, 05:22

Expert's post

bhavinshah5685 wrote:

Al can complete a particular job in 8 hours. Boris can complete the same job in 5 hours. Cody can complete a second job, which requires twice as much work as the first, in 8 hours. If all three people work together on the larger job for 2 hours, how long, in hours, would it take Al, working alone, to finish the job?

Bunuel ,question stem does not mention to find time for Al to complete remaining job. I misunderstood the question and calculated time for Al to finish the whole job.

I understand your point and agree that wording could have been better. Though notice that we are asked "how long, in hours, would it take Al, working alone, to finish the job?" _________________

Hey everyone, today’s post focuses on the interview process. As I get ready for interviews at Kellogg and Tuck (and TheEngineerMBA ramps up for his HBS... ...

I got invited to interview at Sloan! The date is October 31st. So, with my Kellogg interview scheduled for this Wednesday morning, and my MIT Sloan interview scheduled...