The vast majority of first-year engineering students at

Question

The vast majority of first-year engineering students atnBighorn University are registered in Physics 121. Simone is registered in Physics 121; thus it seems likely that she is a first-year engineering student.

Which one of the following statements, if assumed, enables the conclusion above to be properly drawn?

(A) Every engineering student at Bighorn University must pass Physics 121 or an equivalent in order to meet degree requirements.

(B) The number of first-year engineering students at Bighorn University is slightly larger than the total number of students registered in Physics 121.

(C) The engineering program at Bighorn University is highly structured and leaves its students few opportunities to take nonscience elective courses.

(D) There are twice as many Bighorn University students registered in Physics 121 as there are in the first year of the engineering program.

(E) Some engineering students at Bighorn University take Physics 121 in their second year, but none take it in later years.

ReedArnoldMPREP · Accepted Answer

I would counter with a similar question: why a?

If every engineering student must pass Phys 121 (or an equivalent), why does that make it likely that Simone is a first year engineering student?

We are told that a vast majority of first-year engineering students are registered for PHYS 121. And Simone is registered for Physics 121. The conclusion is that it's likely she's a first year engineering student.

But consider this similar construction.

Most of my cups are in my kitchen. Item A is in my kitchen. Therefore, it is likely that item A is a cup.

Take a moment to try to understand why this reasoning is flawed, and apply the same reasoning to the situation at hand.

Does it make the conclusion more likely if I say "every cup in my house must, from time to time, be in the kitchen for washing." No, this doesn't help me determine if Item A is, in fact, a cup.

The problem is that, while most cups are in my kitchen, there are lots of *other items* in my kitchen as well. So why should Item A be likely to be a cup? That is only true if a majority of the *items in my kitchen* are cups.

Same thing in this problem: Simone is likely a first year engineering student only if Physics 121 is mostly first year engineering students (which isn't the same thing as saying most first year engineering students are in Phys 121).

anishahulkat · Answer

D says No of students registered for physics is greater than the number of first year students, which means they can be from any other year. So out conclusion doesn’t hold. Hence no D. Thanks !!

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pinakinjsaojoij · Answer

There are twice as many Bighorn University students registered in Physics 121 as there are in the first year of the engineering program.

in PHYSICS 121 there are more students than first year of the engineering program. that doesn't means that every students from physics is from first year, there might be more students from other programs.

AndrewN · Answer

Hello,  abhivicks . I agree with the response provided above. I will add that the passage and question frame might feel a bit different to you from what you might see on the GMAT™, enough to make you doubt your approach. I will confess that I ran through all five answer choices before I came back and discovered the correct line of reasoning. Note that this assumption is not required, but is rather something that sufficiently bridges the gap between the premise and conclusion in the last line of the passage. Also, because the conclusion itself is not absolute—it only seems  likely  that Simone is a first-year engineering student—our goal should be to find an answer that makes debating that likelihood more challenging.

There are really two targets here. First, as Reed explained, we are not interested in gathering more information about  every engineering student  without knowing whether Simone is herself an engineering student. That is what we need to ascertain. I think that  or an equivalent  also warrants caution, because it opens the door to even engineering students not having to take Physics 121, the very premise that leads to the conclusion in the passage.

Granted, we have to lean on the adverb  slightly  a lot to see how this option works, but that one word makes a huge difference. If there were 100 students in Physics 121 and there were, say, 120 total first-year engineering students, in light of the fact that, as the first line of the passage tells us,   he vast majority of first-year engineering students at Bighorn University are registered in Physics 121 , we might reasonably interpret  vast majority  to mean what, 90 of those 120? (Even 75 percent would be a little conservative.) That would mean 90 out of 100 students in our little scenario were first-year engineering students taking Physics 121, and there would, in fact, be a pretty high likelihood that Simone was one of those 90—not definite, but  likely , just as the conclusion says.

Like (A), this answer choice tells us more about the engineering program, but we have no idea whether Simone belongs to the program, so this information could be completely irrelevant.

If we wanted to look for a weakener, this would be as close as we have come thus far. If we take the same 100 students from before who registered for Physics 121, this answer choice is saying that there are only 50 students who are  even in  the first year of the engineering program. This would mean that, again, in light of the first sentence of the passage, there would be a 50/50 chance at best that Simone was a first-year engineering student—and that is interpreting  the vast majority  as  all . Thus, it would seem less likely that, if the above were true, Simone would be a first-year engineering student.

Not only is this answer choice tucked away within a  some  condition (we cannot quantify this term in the absence of actual numbers), we also would have no way of telling whether Simone was likely a  first-year  engineering student. She could be one of those  some  not belonging to  the vast majority of first-year engineering students  who registered for the course.

Of the five answer choices, only (B) is tenable. As LSAT questions go, this is one of the more relatable questions for GMAT™ purposes, but I would still steer clear of them unless I had expert guidance (someone such as  GMATNinja  hand-selecting questions for practice).

Good luck with your studies.

- Andrew

VerbalBot · Answer

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The vast majority of first-year engineering students at

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