Logical reasoning PrepTest 144 · Section 4 · Question 24

Incorrect. The argument relies on the counterexample of those who are unenthusiastic passing to prove it's point, so it doesn't require a second counterexample to prove the point—it just requires the counterexample it uses to be relevant.

Incorrect. The Professor's argument is about whether using classes as a proving grounds has worked, not whether it's necessary to have proving grounds set up, so this answer is out of scope.

Incorrect. The goal of the "proving grounds" classes—the one the Professor says isn't met—is to weed out those who aren't fully committed—not to let everyone through who is fully committed. The Professor is trying to show that some people who didn't get through did, but it's out of scope if others who "should" have made it through didn't.

Correct. Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Strengthen with Necessary Premise

Stimulus Summary:
Some intro science courses are meant to weed out those who aren't fully committed to a science major, but studies show that some students who are least enthusiastic pass. Therefore, these courses aren't serving their purpose of weeding uncommitted students out.

Answer Anticipation:
This argument is a bit of a tricky one as there's a subtle but key shift between the groups being discussed in the premises.

The first premise notes that the intro classes are meant to weed out those who aren't "most committed" to the science major. However, when discussing the actual outcome from these classes, it talks about students who are "least enthusiastic" about science. While those can seem like synonyms, whenever a term shifts like that, you should ask yourself if they truly are synonyms. One way to do it? As yourself if someone can be one but not the other.

Can someone be very committed to being a science major while being very unenthusiastic about science? Sure—maybe the person only wants to major in science to open up lucrative career paths, or maybe they want to be a surgeon. Since the two terms aren't the same, the premises shifts between the groups of students it's talking about and is thus flawed. The correct answer should establish that the least enthusiastic students are also the least committed in order to bring those premises together.

How are we supposed to note such a subtle shift? Well, we know from experience that the LSAT will frequently jump between different groups without explicitly calling it out, so we should always be on the lookout for who a premise is talking about.

Answer Explanation:
This answer choice establishes that the students who are least enthusiastic about science aren't those who are most committed to being a science major (once you get past the double negative). That's the connection the argument required to work. If the students who are least enthusiastic about science are also among those most committed to being science majors, then their example doesn't show that the intended purpose of these intro classes is failing and the argument falls apart.

Key Takeaway:
The groups that premises are discussing are important and frequently an issue in an argument. Always pay attention to the way that these groups are described and note any shifts that might be creating a gap in the logic.

Incorrect. This answer is a step past the argument. The Professor never goes on to make a recommendation or suggest that things change—so it doesn't rely on this answer being true.