Q3 - Joan got A's on all

[LSAT-Chang]

Could someone provide me an explanation as to why (C) is wrong? I picked (B) but I didn't have a clear reason to eliminate (C). I thought (B) and (C) were basically the same thing but just that (C) was more general and (B) was more specific to the situation. Also, I thought (C) would be a flaw since it could be possible that hw assignments accounted for 90% of the class grade, 5% term paper, 5% class presentation. So since the author is assuming that Joan has to do the class presentation to pass the course since she didn't get an A on her term paper, it is overlooking the importance of class presentations to her grade (like I said, what if it only accounts for 5%.. then she could pass anyway).

[timmydoeslsat]

Could someone provide me an explanation as to why (C) is wrong? I picked (B) but I didn't have a clear reason to eliminate (C). I thought (B) and (C) were basically the same thing but just that (C) was more general and (B) was more specific to the situation. Also, I thought (C) would be a flaw since it could be possible that hw assignments accounted for 90% of the class grade, 5% term paper, 5% class presentation. So since the author is assuming that Joan has to do the class presentation to pass the course since she didn't get an A on her term paper, it is overlooking the importance of class presentations to her grade (like I said, what if it only accounts for 5%.. then she could pass anyway).

A on term paper ---> Pass without doing class presentation

~A on term paper
____________________________________________________

~ Pass without class presentation (Have to do one to pass)

This is the reasoning the author used. As we can see, it is a classic double negation of a conditional relationship, which we know is invalid.

I think (C) would have been more attractive if it had said "Overlooks importance of HOMEWORK ASSIGNMENTS to a student's overall course grade.

In fact, I believe that such an answer would not exist on this question because that can be viewed as a correct criticism.

It could be the case that Homework Assignments accounts for 99% of your grade and the term paper was 1%.

B is correct on this question. It shows that the author was assuming that ~A on term --->~Pass without presentation

Notice that from the given premises...we DO NOT KNOW WHAT HAPPENS if NOT A on term paper.

We know what happens when we do.

We know nothing of what happens when we DONT have that sufficient condition.

[WaltGrace1983]

There were definitely some attractive answer choices on this one (very surprising considering it is only Q3) so I would like some justification from one of the LSAT geeks to see if my reasoning is correct, if possible.

The Argument:

("A" on term paper --> Able to pass the course w/o presentation)
+
~"A" on term paper

-->

~Able to pass the course w/o class presentation

My initial thoughts brought me back to my own days of gaming the system . I would always ask myself the question, "How well do I need to do on these papers and quizzes and tests in order to be able to get an A in the course by just PASSING the final?" In Joan's situation, if she got an A she would definitely be able to pass the course without doing a presentation. However, does this necessarily mean that getting an A is NECESSARY? Maybe she can get a C+ on the term paper and still not have to do the presentation. After all, all the author says is that getting an A will guarantee her the ability to pass the course without the presentation. The argument is essentially a mistaken reversal, it is confusing what is SUFFICIENT with what is NECESSARY. It looks like this:

Able to pass w/o presentation --> ~A
~A --> ~Able to pass w/o presentation

With this in mind, I go to the answer choices.

I think that (A) and (D) are all basically the same answer choice just worded differently.

(A): the whole argument is about this! This is saying that she must either have an A or she must do the presentation. This is presuming that ~A = presentation and ~presentation = A. (side note: is there a difference between "or" and "either/or" in LSAT land? I feel that "either/or" promotes exclusivity while "or" obviously does not)

(D): this is the contrapositive of the premise! (D) is saying ~Able to pass w/o the presentation --> ~A (or A --> Able). Once again, this is essentially what the argument is about.

(E) is clearly out of scope. So what if "some students" get A's but don't pass the course. We are just talking about Joan and, in Joan's case, getting an A is sufficient to pass the course.

(C) is a bit more tricky but I don't think the argument is doing this because it is saying that if you don't get an A then the only way to pass the class is to do the presentation. Also, I think that this is a trick answer for people that get "homework," "term paper," and "presentation" confused. I think that the argument may be potentially over-emphasizing the importance of the term-paper or maybe undermining the importance of homework. This is the line of thought that I believed the flaw would derive from originally.

(B) This is getting at the whole illegal reversal. The argument is saying A --> ~Presentation but concluding ~A --> Presentation. In other words, it "presupposes" that ~A definitely means P.

[MeiL57]

There were definitely some attractive answer choices on this one (very surprising considering it is only Q3) so I would like some justification from one of the LSAT geeks to see if my reasoning is correct, if possible.

The Argument:

("A" on term paper --> Able to pass the course w/o presentation)
+
~"A" on term paper

-->

~Able to pass the course w/o class presentation

My initial thoughts brought me back to my own days of gaming the system . I would always ask myself the question, "How well do I need to do on these papers and quizzes and tests in order to be able to get an A in the course by just PASSING the final?" In Joan's situation, if she got an A she would definitely be able to pass the course without doing a presentation. However, does this necessarily mean that getting an A is NECESSARY? Maybe she can get a C+ on the term paper and still not have to do the presentation. After all, all the author says is that getting an A will guarantee her the ability to pass the course without the presentation. The argument is essentially a mistaken reversal, it is confusing what is SUFFICIENT with what is NECESSARY. It looks like this:

Able to pass w/o presentation --> ~A
~A --> ~Able to pass w/o presentation

With this in mind, I go to the answer choices.

I think that (A) and (D) are all basically the same answer choice just worded differently.

(A): the whole argument is about this! This is saying that she must either have an A or she must do the presentation. This is presuming that ~A = presentation and ~presentation = A. (side note: is there a difference between "or" and "either/or" in LSAT land? I feel that "either/or" promotes exclusivity while "or" obviously does not)

(D): this is the contrapositive of the premise! (D) is saying ~Able to pass w/o the presentation --> ~A (or A --> Able). Once again, this is essentially what the argument is about.

(E) is clearly out of scope. So what if "some students" get A's but don't pass the course. We are just talking about Joan and, in Joan's case, getting an A is sufficient to pass the course.

(C) is a bit more tricky but I don't think the argument is doing this because it is saying that if you don't get an A then the only way to pass the class is to do the presentation. Also, I think that this is a trick answer for people that get "homework," "term paper," and "presentation" confused. I think that the argument may be potentially over-emphasizing the importance of the term-paper or maybe undermining the importance of homework. This is the line of thought that I believed the flaw would derive from originally.

(B) This is getting at the whole illegal reversal. The argument is saying A --> ~Presentation but concluding ~A --> Presentation. In other words, it "presupposes" that ~A definitely means P.

Then, I don't understand why A is right answer, eliminate D.