#3 - According to the rules of the university's housing

[Administrator]

Complete Question Explanation

Must Be True-SN. The correct answer choice is (D)

This stimulus provides us with a clear set of rules, which can be diagrammed as follows:

Statement 1: The only students guaranteed dorm rooms are fourth year students:
guaranteed dorm room 4th year student

Statement 2: Fourth years on dean’s list can choose before any non-fourth year student.
Fourth year on dean’s list choose before any non-fourth year

Answer choice (A): Based on Statement 1 above, Benizer, a fourth year student, might be guaranteed a dorm room. The fact that Benizer is not on the Dean's list does not mean she is not guaranteed a dorm room.

Answer choice (B): As we can see from Statement 2 above, being on the dean’s list does not, according to the information supplied, give priority to one fourth year over another (additionally, the fact that Ivan is not on the dean’s list should certainly not give him priority).

Answer choice (C): The stimulus tells us that only fourth year students are guaranteed dorm rooms, so Halle, a third year, enjoys no such guarantee (even if she is on the dean’s list).

Answer choice (D): This is the correct answer choice, providing all of the necessary information to validate its conclusion: According to Statement 2 above, Gerald, a fourth year on the dean’s list, can choose a dorm room before any non-fourth-year student (even dean’s list-member Katrina, who is only a third-year student).

Answer choice (E): We can again refer to Statement 2 above in order to disprove this answer choice. Anissa, a fourth year member of the dean’s list, can choose a dorm room before any non-fourth-year student—thus Jehan, a non-fourth year student, doesn’t even have a guaranteed dorm room, and certainly does not have the right to choose before Anissa. Therefore this answer choice is incorrect.

[ellenb]

Dear Powerscore,

I just had a quick question on this question . I know that "the only" introduces the sufficient condition, however, in the explanation "the only students guaranteed dormitory" is diagramed as the necessary.

Please explain why it is introduced as a necessary instead as a sufficient.


I seem to know that:

Ex: The only fruits are apples

F->A

However, the answer is trying to say that A->F
where "the only" introduces the sufficient. That is from what I know why they diagramed the stimulus differently.



Thanks

Ellen

[Nikki Siclunov]

Hi Ellen,

Here's how I'd diagram this:

"The only students guaranteed dorm rooms are 4th year students":

Guaranteed dorm room 4th year student

Also, any 4th year student on the dean's list can choose a dorm room before anyone who is not a 4th year student:

4th year student + Dean's List Choose

These rules prove answer choice (D) to be correct.

[ellenb]

so the only typically introduces a sufficient condition?

thanks Nikki

[Dave Killoran]

Hey Ellen,

Please check out this thread: http://forum.powerscore.com/lsat/viewto ... =12&t=2479 for more info on diagramming "the only." I think you may find it helpful.

Thanks!

[ellenb]

Dear Powerscore,

I had a quick question with the diagramming of the stimulus for this question

when we have:

the only students guaranteed dormitory rooms are fourth-year students

Since "the only" combination is introducing a sufficient condition we will have

Students guaranteed dormitory rooms-->Fourth-year students

However, it is diagrammed differently in the explanations, it is reversed.

Fourth-year students-->Students Guaranteed Dormitory Rooms why is that?

Thanks in advance

Ellen

[David Boyle]

Dear Powerscore,

I had a quick question with the diagramming of the stimulus for this question

when we have:

the only students guaranteed dormitory rooms are fourth-year students

Since "the only" combination is introducing a sufficient condition we will have

Students guaranteed dormitory rooms-->Fourth-year students

However, it is diagrammed differently in the explanations, it is reversed.

Fourth-year students-->Students Guaranteed Dormitory Rooms why is that?

Thanks in advance

Ellen

Hello Ellen,

By the way, with this question, and also the previous one ("# 7"), it can help not only to give the question number but also the section ("MN/MR/Contrapositive Questions"). Thanks!
Anyway, you're ahead of the curve by saying, "Since "the only" combination is introducing a sufficient condition": I didn't think everyone knew that!

I can't exactly say why things are diagrammed the way they are in the explanations, although common-sensically, a rule like the one in the stimulus, if you think about real-life scenarios at universities, could mean something like "if and only if", i.e., if you're guaranteed, you're a 4th year; if you're a 4th year, you're guaranteed. (E.g., it could be strange for a college to have a rule saying, "If you're a senior, you're MAYBE guaranteed a dorm room, but we're not sure"!) But it's true that it doesn't say that in the stimulus per se. So thanks for mentioning that.

Hope that helps,
David

[ellenb]

Thanks David, I am glad I surprised you in a nerdy way about my knowlege of this rule.

So, I have learned it a while back that "the only" introduces a sufficient condition, does it still hold true these days?

Also, does my diagram is right and they did something incorrect in the explanations. I understand your anaglogy, but since this is a MBT and conditonal I would prefer to know exactly how to diagram it. Since, we cannot really bring outside knowledge into the stimulus.

Basically, I do not want to assume if and only if statement, if I have not specifically been told so in the stimulus.

thanks in advance!

Ellen

[David Boyle]

Thanks David, I am glad I surprised you in a nerdy way about my knowlege of this rule.

So, I have learned it a while back that "the only" introduces a sufficient condition, does it still hold true these days?

Also, does my diagram is right and they did something incorrect in the explanations. I understand your anaglogy, but since this is a MBT and conditonal I would prefer to know exactly how to diagram it. Since, we cannot really bring outside knowledge into the stimulus.

Basically, I do not want to assume if and only if statement, if I have not specifically been told so in the stimulus.

thanks in advance!

Ellen

Hello,

"The only" still should mean a sufficient condition--I'm glad you learned that a while ago!!
I would diagram it the way you did. Good job!

David

[ellenb]

I am still puzzled as to why they put the "the only" sufficient condition in the necessary part of the statement.

They have in the explanations:

4th year--> guaranteed

However, since we are following "the only" rule to be in the sufficient condition, it should be int the sufficient condition.

Thus, we would have:

Guaranteed--> 4th year

Thanks,

Ellen