GRE Prep 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
Track
Your Progress
Practice
Pays
- Jun 07
Free GRE Practice Test and Personal Score Assessment
10:00 AM PDT
-11:00 AM PDT
You’ll get a baseline score estimate as well as a performance breakdown by question types so that you can learn more about your strengths and weaknesses.
GRE Math Challenge #27-Working alone jerry can complete
[#permalink]
Updated on: 17 Feb 2020, 11:48
3
2
Expert Reply
6
Bookmarks
00:00
Question Stats:
Hide Show timer Statistics
Working alone Jerry can complete a work in 6 minutes.Working alone ,Adam can complete a work in 8 minutes.Working together,Jerry leaves the work after 2 minutes.How long will it take Adam to complete the work?
Show: :: OA
200 seconds
Retired Moderator
Joined: 10 Apr 2015
Posts: 6218
Given Kudos: 136
Re: GRE Math Challenge #27-Working alone jerry can complete
[#permalink]
15 Nov 2015, 20:43
3
sandy wrote:
Working alone Jerry can complete a work in 6 minutes.Working alone ,Adam can complete a work in 8 minutes.Working together,Jerry leaves the work after 2 minutes.How long will it take Adam to complete the work?
Let's assign a NICE VALUE to the job that needs to be completed.
We have completion times of 6 minutes and 8 minutes, so let's say the "job" consists of making 24 widgets (I chose this value, because 6 and 8 both divide nicely into 24)
Jerry can complete a [job] in 6 minutes
If the job is to make 24 widgets, we can see that Jerry can make 4 widgets/minute
Adam can complete a [job] in 8 minutes
If the job is to make 24 widgets, we can see that Adam can make 3 widgets/minute
Given: they work together for 2 minutes.
Together, their combined output = 4 widgets/minute + 3 widgets/minute = 7 widgets/minute
So, in 2 minutes, their TOTAL output = (2 minutes)(7 widgets/minute) = 14 widgets
If the total job is to make 24 widget, then there are still 10 widgets to make (24 - 14 = 10)
Then Jerry leaves
Adam can make 3 widgets/minute.
He must make 10 widgets
Time = output/rate = 10/3 = 10/3 minutes
Answer: 10/3 minutes or 200 seconds
Cheers,
Brent
Re: GRE Math Challenge #27-Working alone jerry can complete
[#permalink]
06 Jan 2016, 05:14
1
They work 2 min together, so jerry did 1/3 work and adam did 1/4 work. so they did 7/12 work together in 2minutes.
remained 5/12 work for adam alone, he can do this work alone in 5/12*8min*60sec=200sec.
remained 5/12 work for adam alone, he can do this work alone in 5/12*8min*60sec=200sec.