3 categories of workers

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3 categories of workers

by amsm25 » Fri May 18, 2012 8:09 pm
A factory employs 3 categories of workers, A, B and C. The efficiency of the 3 categories of workers to do a specific task is in the ratio of 3 : 5 : 6 respectively and the factory employs 15 of category A, 12 of category B and 3 of category C. If the total wages paid to the entire group of 30 workers is $492 per hour, what will be the wages earned by a category C worker for an 8-hour day?

A. $24

B. $144

C. $192

D. $72

E. $576


OA - c

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by Stuart@KaplanGMAT » Fri May 18, 2012 10:04 pm
amsm25 wrote:A factory employs 3 categories of workers, A, B and C. The efficiency of the 3 categories of workers to do a specific task is in the ratio of 3 : 5 : 6 respectively and the factory employs 15 of category A, 12 of category B and 3 of category C. If the total wages paid to the entire group of 30 workers is $492 per hour, what will be the wages earned by a category C worker for an 8-hour day?

A. $24

B. $144

C. $192

D. $72

E. $576


OA - c
Hi!

This is a very poorly worded question and makes little sense. What does "the efficiency of the 3 categories of workers" mean? How is it related to wage? Nowhere does it say that different workers get different hourly rates (e.g. that hourly wages are proportional to efficiency, whatever that actually means), so there's no way to actually solve the problem.

You will never see this kind of ambiguous wording on the actual GMAT.

What's the source?
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by mathbyvemuri » Fri May 18, 2012 10:14 pm
Wages are paid in the ratio of efficiencies.

efficiencies ratio = 3:5:6
No. of employees A,B,C = 15,12,3
wages paid per employee categories in the ratio = (3*15) : (5*12) : (6*3) = 45:60:18
Total wages paid per hour = 492
=> wages paid per hour to C group employees
= (18/123)*492
= 18*4
wages paid per hour to one C group employee = 18*4/3 (As there are 3 C-group employees)
wages paid for 8-hours to one C group employee = 18*4*8/3 = 192
Answer "C"
Last edited by mathbyvemuri on Sat May 19, 2012 1:48 am, edited 1 time in total.

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by Stuart@KaplanGMAT » Fri May 18, 2012 10:21 pm
mathbyvemuri wrote:Wages are paid in the ratio of efficiencies.
Where do you see that information in the question stem?

Also, does a higher number in the ratio mean that a worker is more efficient or less efficient? For example, if you measure efficiency in tasks per hour, then higher is better; but if you measure efficiency in hours per task, then lower is better.

Again, a question like this would never appear on the actual GMAT.
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by mathbyvemuri » Sat May 19, 2012 1:46 am
Stuart Kovinsky wrote: Where do you see that information in the question stem?

Also, does a higher number in the ratio mean that a worker is more efficient or less efficient? For example, if you measure efficiency in tasks per hour, then higher is better; but if you measure efficiency in hours per task, then lower is better.

Again, a question like this would never appear on the actual GMAT.
You are right Stuart. But if at all such type of "wrongly worded" or "not sufficiently informed" question appears, some information may be taken granted. Or else, there may be no choice. "Ratio of efficiencies" is wrongly coined word and is not generally used. But, as it is used, I took " Better Efficiency" in a progressive sense, that is "Better number of tasks per unit time".

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by Stuart@KaplanGMAT » Sat May 19, 2012 7:25 am
mathbyvemuri wrote: You are right Stuart. But if at all such type of "wrongly worded" or "not sufficiently informed" question appears, some information may be taken granted. Or else, there may be no choice. "Ratio of efficiencies" is wrongly coined word and is not generally used. But, as it is used, I took " Better Efficiency" in a progressive sense, that is "Better number of tasks per unit time".
Hi again!

I strongly disagree - you will never have to make assumptions of this nature on the actual GMAT and doing so in practice will lead to habits on test day that could lead to fatal errors. For example, one of the most common DS mistakes is to assume facts that aren't actually in evidence.

So, instead of trying to figure out what the question was "supposed to mean", it's far better to completely ignore the question, find the source and make sure that you avoid questions from that source in the future.

There are lots of great examples of GMAT questions avaiable - stick to the reputable sources if you want realistic practice.
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