I am really struggling with these types of problems....
At his hourly rate, Don had estimated the labor cost of a repair job as $336 and was paid that amount. However, the job took 4 hours longer than he had estimated and, consequently, he earned $2.00 per hour less than his regular hourly rate. What was the time Don had estimated for the job, in hours?
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- Anju@Gurome
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Let us assume that the regular hourly rate = R, and the estimated time = Tcpay3245 wrote:At his hourly rate, Don had estimated the labor cost of a repair job as $336 and was paid that amount. However, the job took 4 hours longer than he had estimated and, consequently, he earned $2.00 per hour less than his regular hourly rate. What was the time Don had estimated for the job, in hours?
So, RT = 336
Also, (R - 2)(T + 4) = 336
So, RT = (R - 2)(T + 4)
--> RT = RT - 2T + 4R - 8
--> T = 2R - 4
Now we can plug in answer choices for T and get the value of R. The option which gives the product of RT as 336 will be the correct answer.
In the original problem, the options are as follows...
A. T = 28 ---> R = (28 + 4)/2 = 16 ---> RT = 28*16 ≠336A. 28
B. 24
C. 16
D. 14
E. 12
B. T = 24 ---> R = (24 + 4)/2 = 14 ---> RT = 24*14 = 336
As there will be only one correct option, the correct answer must be B.
Anju Agarwal
Quant Expert, Gurome
Backup Methods : General guide on plugging, estimation etc.
Wavy Curve Method : Solving complex inequalities in a matter of seconds.
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Quant Expert, Gurome
Backup Methods : General guide on plugging, estimation etc.
Wavy Curve Method : Solving complex inequalities in a matter of seconds.
§ GMAT with Gurome § Admissions with Gurome § Career Advising with Gurome §
That is fantastic Anju. I really appreciate you showing me a much simpler approach than the book. I just get really stuck tryng to work out how to answer questions like these and waste 5-10minutes on them...
Is there any special approach I should be adopting?
Is there any special approach I should be adopting?
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- Anju@Gurome
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As I always suggest, do not stick to one particular approach.cpay3245 wrote:Is there any special approach I should be adopting?
Most of the problems in GMAT can be solved in more than method. It is difficult to teach when to use
which method. That way students end up sticking to a method which works best for a particular problem but not so good (often fails) for other problems on the same concept.
Solve any problem with as much methods as you can. Only then you'll learn the trick of always identifying the best method.
Here is a post I made which will you give you a general idea on this >> https://www.beatthegmat.com/a-question-a ... tml#616795
Anju Agarwal
Quant Expert, Gurome
Backup Methods : General guide on plugging, estimation etc.
Wavy Curve Method : Solving complex inequalities in a matter of seconds.
§ GMAT with Gurome § Admissions with Gurome § Career Advising with Gurome §
Quant Expert, Gurome
Backup Methods : General guide on plugging, estimation etc.
Wavy Curve Method : Solving complex inequalities in a matter of seconds.
§ GMAT with Gurome § Admissions with Gurome § Career Advising with Gurome §
- GMATGuruNY
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We can plug in the answers, which represent the estimated time: 28, 24, 16, 14, or 12.At his regular hourly rate, Don had estimated the labor cost of a repair job as $336 and he was paid that amount. However, the job took 4 hours longer than he had estimated and, consequently, he earned 2$ per hour less than his regular hourly rate. What was the time Don had estimated for the job, in hours?
28
24
16
14
12
The actual time was 4 hours longer: 32, 28, 20, 18, or 16.
Since 336 is not a multiple of 32, eliminate A.
Since 336 is not a multiple of 20, eliminate C.
336 is not a multiple of 9, since the sum of its digits is not a multiple of 9.
Thus, 336 is not a multiple of 18; eliminate D.
The correct answer must be B or E.
Answer choice B: estimated time = 24, actual time = 28
Estimated payrate = 336/24 = 14.
Actual payrate = 336/28 = 12.
Difference = 14-12 = 2.
Success!
The correct answer is B.
Note that we had to try only ONE answer choice -- a very efficient way to solve the problem.
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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