Some students attending a small university with a well-known choir liv

Question

Some students attending a small university with a well-known choir live off campus. From the fact that all music majors are members of the choir, a professor in the music department concluded that none of the students who live off campus is a music major.

The professor’s conclusion is properly drawn if which one of the following is assumed?

(A) None of the students who live off campus is a member of the choir.
(B) None of the students who are music majors has failed to join the choir.
(C) Some of the students who do not live off campus are not music majors.
(D) All students who live on campus are music majors.
(E) All students who are members of the choir are music majors.

Bunuel · Accepted Answer

EXPLANATION FROM Fox LSAT

You could diagram this question if you needed to, but as much as possible I try to answer the question without a diagram. Diagrams add a level of abstraction that make it more likely that I’ll make silly mistakes. Before doing a diagram, I always see if I can poke a hole in the argument.

Here, the argument has a giant hole in it. Fact: Some students live off campus. Fact: All music majors are members of the choir. Totally bogus, unwarranted, nonsensical conclusion: None of the students who live off campus are music majors.

The question asks to identify an assumption that, if true, “allows the conclusion to be properly drawn.” This is a Sufficient Assumption question.

On a Sufficient Assumption question, you should pretend that you’re the attorney for the speaker, and you’re hiring an expert witness who will help you win. This expert is going to cost you thousands of dollars per day: you’re going to fly him first class, put him up at the Four Seasons, and pay his $5,000-per-day consulting fee. If you’re paying that kind of money, you’re going to require him to say  exactly what you want him to Goddamn say . Okay then, Counselor. What do you want him to say?

In order to win your case, you need the expert to plug the giant hole in your client’s **** argument. I can plug it for you: “No members of the choir live off campus.” If that’s true, then it connects the evidence, “All music majors are members of the choir,” to the desired conclusion, “No music majors live off campus.” If I can find an expert who will say, “All members of the choir live on campus,” then I think our client wins.

Each answer choice is a potential expert for hire; let’s see if one of them is the guy for the job.

Note that our prediction does prove a lot  more  than what we really need to prove. We don’t  necessarily  need to prove that every member of the choir (whether or not they are music majors) lives on campus. Those folks aren’t part of our case, and are therefore irrelevant to me. But we shouldn’t care if our prediction proves too much here. Since all music majors  are  members of the choir, if the entire choir lives on campus, then all the music majors live on campus. The answer we have predicted is more than the minimum that’s necessary, but it’s  sufficient  to prove our case, and that’s all we care about here: winning.

A) Well, this is just another way of saying, “All choir members live on campus,” and that’s exactly what we were looking for. If we put this guy on the stand, I don’t see how we could lose. I’m pretty sure this guy is hired, but let’s interview the rest of the candidates briefly, just to be sure.

B) This answer choice restates something that’s already in the evidence. Saying something twice doesn’t make our case any stronger. Next please.

C) What? I hate the double negative here, and I also hate the use of the word “some.” Our desired conclusion was absolute (it uses the word “none”), and in order to make a bold conclusion we need some bold evidence. This expert isn’t saying what we want him to say. Fired.

D) Just because all students who live on campus are music majors doesn’t prove that all music majors live on campus. The arrow only goes one way. Example: All Giants are baseball players, but that doesn’t prove that all baseball players are Giants. This guy is an idiot. Next.

E) This doesn’t connect the choir to on or off campus; I don’t see how this can possibly prove our case. But we don’t care, because we’ve already fallen in love with A.

Our answer is A, because Expert A, on the witness stand, will guarantee we win our case.

chetan2u · Answer

Three categories  
1) Music major: A
2) Member of choir:B
4) Living off campus: C

Given . 
All A are B. 
Conclusion- No C is A.

Gap : No connection between C and A or B.

Option A says that No C is B.

As all As are B, no C is B means no C is A.

Option A is correct.

Raman109 · Answer

Understanding the argument - 
Some students attending a small university with a well-known choir live off campus. - It means "some students live off campus." Which is "a small university with a well-known choir." The university has a well-known choir; some students are part of the university and not necessarily part of the choir.

From the fact that all music majors are members of the choir, a professor in the music department concluded that none of the students who live off campus is a music major.

The professor’s conclusion is properly drawn if which one of the following is assumed?

We need to find the missing premise.

(A) None of the students who live off campus is a member of the choir. - Yes. 
(B) None of the students who are music majors has failed to join the choir. - Out of scope. 
(C) Some of the students who do not live off campus are not music majors. - Out of scope. 
(D) All students who live on campus are music majors. - No
(E) All students who are members of the choir are music majors. - No

VerbalBot · Answer

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Some students attending a small university with a well-known choir liv

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