Nearly all employees of the factory who have completed their high scho

Question

Nearly all employees of the factory who have completed their high school diploma have earned their factory safety certificate, having easily completed the eight week training course. The high school graduates who haven't earned the certificate are ones who have evening obligations that have prevented them from taking the course. Overall, though, most of the factory workers have not earned the certificate.

If the statements above are true, which one of the following also must be true?

A. A large proportion of students with high school diplomas have evening obligations that have prevented them from taking the eight week training course.

B. No factory worker without a high school diploma has completed the course and earned the certificate.

C. Most of the workers who have earned the certificate are high school graduates.

D. A large proportion of the factory workers have not graduated from high school.

E. Most of the people who take the training course are able to earn the safety certificate.

Bunuel · Answer

OFFICIAL EXPLANATION

The credited answer is (D). If most factory workers with high school degrees have completed the training, then most of the factory workers who haven't completed the training must be folks without high school degrees. Since the factory workers who haven't completed the training in the vast majority, and since factory workers with high school degrees can only account for a very small number of these, then most of the factory workers must not have high school degrees.

We don't know how many factory workers with high school degrees have evening obligations. We know that the factory workers with high school degrees who haven't completed the training have evening obligations that prevent them from completing it, but among the factory workers with high school degrees who have completed the training, we don't know what proportion has evening obligations, and how the size of this group might compare to the number of the factory workers with high school degrees who haven't completed the training. Choice (A) is incorrect.

As explained above, the information lead us to deduce that many factory workers without high school degrees haven't completed the training course, but that does mean that none have. Choice (B) is too extreme, and it is incorrect.

We don't know the relative proportions of worker with or without high school degrees; as discuss above, we have grounds to suspect that the latter is a larger group. We know that many of the factory workers with high school degrees have completed the training and have earned the certificate, but we have no idea what proportion of the factory workers without high school degrees have done so, and how the number of this latter group compares to the former group. We have no way to know which is greater. Choice (C) is incorrect.

The information suggests that, among high school graduates, most of the folks who took the course were able to earn the certificate with little difficulty. Is this generally the case? Is it the case for folks who weren't able, for whatever reason, to complete their high school degree? We don't know. The prompt provides no information on this point. Choice (E) is incorrect.

AdityaAzad15 · Answer

One can consider that, the large proportion that has not completed the training are those that have completed their GED but have evening obligations?

nikhilvsh · Answer

Is the High School Diploma and High School Degree same?

Abhishek009 · Answer

No absolutely not , this is the CRUX HSD = High School Diploma HSG = High School Graduate FSC = factory safety certificate There is a clear line of difference, excellently hidden in the stimulus, just catch the thief and U will reach the Answer.

RishS94 · Answer

I understand the confusion, and I appreciate your patience. Let's clarify this:
In the context of the question, "high school diploma holders" and "high school graduates" are intended to refer to the same group of people—those who have completed high school. The passage is not distinguishing between two separate groups of high school completers; rather, it uses these terms interchangeably.
The logic behind answer choice (D) is based on the following: 
 
   Nearly all high school graduates  have earned the factory safety certificate.  
   Most factory workers  have not earned the certificate.   
 From these statements, we can infer that if nearly all high school graduates have the certificate, yet most factory workers do not, then a large proportion of the factory workers must not be high school graduates. This is because the group of high school graduates without the certificate is small and cannot account for the majority of factory workers lacking the certificate.
The conclusion does not depend on the relative size of the high school graduate population compared to the overall factory worker population. It hinges on the fact that the majority of factory workers without the certificate must be those who did not graduate from high school.
I hope this clears up the confusion. If you have any more questions, feel free to ask!

RiyaJ0032 · Answer

Hi  MartyMurray !

Could you please clear this doubt -

for (D) to hold, wouldn't it be true that to have a safety certificate, one needs to be a high school grad (or high school diploma holder)

but we are not given this relationship

it can be that one has a safety certificate, yet is not a high school grad (unless having the certificate hinges on one being a high school grad)

If any expert could please clarify!
Thank you

KarishmaB 
 GMATNinjaTwo 
 DmitryFarber

DmitryFarber · Answer

This doesn't rely on any guarantee or absolute statement. It's all about proportion. In fact, if some non-grad workers have certificates, that just makes the inference in D even clearer. It limits the # of certificates available for grads, so that there can't be very many of them, considering that "nearly all" of them have certificates.

Let's try some numbers. We're told that most of the workers don't have a certificate. So let's say out of 100 workers, 30 have the certificate and the other 70 don't. Then they say that nearly all of the HS graduates have earned a certificate. There are only 30 certificates, so let's say there are 35 HS grads. Of those, 28 got certificates and the other 7 didn't. That leaves 65 non-grads, among whom 2 people got certificates. Can we stretch it further? Not much. As it is, 28/35 is 80%--that's not really looking like "nearly all." If we put the # of HS grads over 50, then at most 60% of them could have certificates, even if *no* non-grads got a certificate. And again, if we *do* give some certificates to non-grads, it just makes it even worse to try to put the # of grads over 50.

Now you might think 30 was an arbitrary #. We just know that MOST haven't gotten the certificate. That means < 50 got it, so let's test that limit. If 50 people got the certificate, but some HS grads did NOT get it, then it's possible that the # of HS grads exceeds 50. But again, it can't exceed 50 by much, and that's if we don't have any non-grads with certificates. If we do have some, then the # of HS grads is probably 50 or less. So how does D look? All it says is that non-grads make up "a large proportion" of the workforce. It looks like if we stretch to the limit and make an assumption (the very assumption you were questioning), we still end up with about half the workers as non-grads. Below that limit and/or not making that assumption, we see that the majority of workers are non-grads. Either way, it looks safe to say that "a large proportion" of the workers are non-grads.

RiyaJ0032 · Answer

DmitryFarber , got this!
Clear explanation

The clarity of thought is immense!

Nearly all employees of the factory who have completed their high scho

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Nearly all employees of the factory who have completed their high scho

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