work rate problem

This topic has expert replies
Master | Next Rank: 500 Posts
Posts: 123
Joined: Mon Feb 07, 2011 12:11 pm
Followed by:1 members

work rate problem

by rupsk » Fri Jul 22, 2011 6:09 am
I am attaching the problem definition along with explanation but my question is the answer should be twice the correct answer as it has been asked hour of both people not only one. In explanation they have taken x as total hour pay but i had taken x as single person pay. Please explain me where I am wrong.

Thanks
Attachments
work rate.png

User avatar
GMAT Instructor
Posts: 15539
Joined: Tue May 25, 2010 12:04 pm
Location: New York, NY
Thanked: 13060 times
Followed by:1906 members
GMAT Score:790

by GMATGuruNY » Fri Jul 22, 2011 6:24 am
Elana was working to code protocols for computer processing. She did (11/18) of the job and allowed Andy to finish it. They both work at the same rate and receive the same hourly pay. If the difference between the amounts they were paid was $154, what was the total amount the two were paid for the entire coding job?

A. $252
B. $269.50
C. $369.00
D. $423.50
E. $693.00
Work by Elana - work by Andy = 11/18 - 7/18 = 4/18 = 2/9 of the job.
Thus, the difference between Elana's pay and Andy's pay -- 154 -- must be 2/9 of the total pay.
The answers choices represent the total pay.
If we take 2/9 -- less than 1/4 -- of answer choices A, B, C or D, the result will be much less than 154.
Eliminate A, B, C and D.

The correct answer is E.
Last edited by GMATGuruNY on Fri Jul 22, 2011 7:35 am, edited 1 time in total.
Private tutor exclusively for the GMAT and GRE, with over 20 years of experience.
Followed here and elsewhere by over 1900 test-takers.
I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.

As a tutor, I don't simply teach you how I would approach problems.
I unlock the best way for YOU to solve problems.

For more information, please email me (Mitch Hunt) at [email protected].
Student Review #1
Student Review #2
Student Review #3

User avatar
Legendary Member
Posts: 504
Joined: Tue Apr 19, 2011 1:40 pm
Thanked: 114 times
Followed by:11 members

by knight247 » Fri Jul 22, 2011 7:30 am
Can't really figure how u got 369...Can u explain how u solved it?

If Elana did 11/18 of the job and the rest was completed by Andy then Andy did 7/18 of the job

The ratio of work done by both of them is 11/18:7/18. Now multiplying 18 on both sides we have
E:A is 11:7. So if this is the ratio of the amount of work done by them...Then they also have to be paid accordingly. Now assume the total amount distributed among them is $Z. Then Z will be split up in the ration 11:7 making it 11z and 7z respectively. We are given that 11z-7z=154 so 4z=154=38.5

11z=423.5 (Elana's Share)

7z=269.5 (Andy's Share)

Total=693 hence E

Master | Next Rank: 500 Posts
Posts: 123
Joined: Mon Feb 07, 2011 12:11 pm
Followed by:1 members

by rupsk » Fri Jul 22, 2011 8:15 am
I was running out of time so just picked up the answer in guess but when try to solve it after test i did below things
Each of them will take x amount for the work, so
(11-7)*x/18=154
But i think total amount paid will be 2x rather than x.

Junior | Next Rank: 30 Posts
Posts: 13
Joined: Tue Sep 08, 2009 6:55 am
Thanked: 3 times

by atuljadhav » Sat Jul 23, 2011 6:39 pm
Since Elana did 11/18 of the job, Andy did 1-11/18 i.e 7/18 of the job.
Lets assume Y is hourly rate. Since the hourly rate is same, elana gets paid 11/18*Y and Andy gets paid 7/18*Y.

Since the difference in their pay is 154. Solve the equation for 11/18Y-7/18*Y =154. This gives Y= 693.

If you put the same value back into the equation the total paid is $ 693.00.

I hope this approach is correct as well.

Regards

Atul

Master | Next Rank: 500 Posts
Posts: 401
Joined: Tue May 24, 2011 1:14 am
Thanked: 37 times
Followed by:5 members

by MBA.Aspirant » Sun Jul 24, 2011 12:18 am
11/18x - 7/18x = 154

2/9x = 154

x= 693

Newbie | Next Rank: 10 Posts
Posts: 2
Joined: Thu Nov 03, 2016 2:50 am

by suramya26 » Thu Nov 03, 2016 3:01 am
atuljadhav wrote:Since Elana did 11/18 of the job, Andy did 1-11/18 i.e 7/18 of the job.
Lets assume Y is hourly rate. Since the hourly rate is same, elana gets paid 11/18*Y and Andy gets paid 7/18*Y.

Since the difference in their pay is 154. Solve the equation for 11/18Y-7/18*Y =154. This gives Y= 693.

If you put the same value back into the equation the total paid is $ 693.00.

I hope this approach is correct as well.

Regards

Atul

Hi Atul,

I have a small doubt in your solution
Since y is the hourly wage
WOULDN't we multiply it with hours rather than with the work??
I meant that shouldn't it be 18/4*y=$154
and then
y=308/9
NOW we add 18/11*y+18/7*y(reciprocal of work is time)
PLACING VALUE OF y
we get 618/77