LSAT Explanation PT 37, S2, Q3: Joan got A's on all her

LSAT Question Stem

The argument's reasoning is questionable because the argument 

Logical Reasoning Question Type

This is a Flaw question. 

Correct Answer

The correct answer to this question is B. 

LSAT Question Complete Explanation

First, let's analyze the argument in the passage. The passage states that Joan got A's on all her homework assignments, and if she had gotten an A on her term paper, she could pass the course even without doing the class presentation. However, she did not get an A on her term paper, so the author concludes that she will have to do the class presentation to pass the course. The argument can be broken down into the following structure:

Premise: A's on homework assignments

Premise: A on term paper -> Pass course without presentation

Fact: Did not get A on term paper

Conclusion: Must do class presentation to pass the course

Now, let's create an "Evaluate" question about the argument: "Is it possible for Joan to pass the course without doing the class presentation if she doesn't get an A on her term paper?"

The question type for this problem is Flaw, which means we are looking for the answer choice that best describes a flaw in the argument's reasoning.

a) This answer choice suggests that the argument ignores the possibility that Joan must either have an A on her term paper or do the class presentation to pass the course. However, this is not a flaw in the argument's reasoning, as the passage explicitly states that if Joan had gotten an A on her term paper, she could pass the course without doing the class presentation.

b) This is the correct answer. The argument presupposes without justification that Joan's not getting an A on her term paper prevents her from passing the course without doing the class presentation. The argument commits a Mistaken Negation, which means it incorrectly assumes that if the sufficient condition (getting an A on the term paper) is not met, then the necessary condition (passing the course without doing the class presentation) is also not met. This is a flaw in the argument's reasoning.

c) The argument does not overlook the importance of class presentations to a student's overall course grade. The passage is focused on whether Joan needs to do the class presentation to pass the course based on her term paper grade, not the overall importance of class presentations.

d) This answer choice is incorrect because it ignores the fact that the passage already states that Joan did not get an A on her term paper. The argument does not need to consider this possibility because it is already established.

e) This answer choice is irrelevant to the argument because it discusses the possibility that some students get A's on their term papers but do not pass the course. The passage is focused on Joan's specific situation, not the outcomes of other students.

In conclusion, the correct answer is B because the argument's reasoning is flawed due to the unjustified presupposition that Joan's not getting an A on her term paper prevents her from passing the course without doing the class presentation.