Logical reasoning PrepTest 140 · Section 2 · Question 8

Incorrect. Kathy doesn't mention the overall safety record of Qualzan.

Incorrect. Kathy doesn't bring up an argument that's logically parallel to Mark's but flawed—instead, she brings up a new consideration.

Incorrect. Kathy doesn't question the study that Mark mentions, or even the scientific fact of the similar mechanism by which the two drugs operate.

Incorrect. Kathy does try to undermine Mark's argument, but she doesn't appeal to a fundamental principle of medicine. Rather, she brings up a specific point of comparison between the two drugs being discussed.

Correct. Argument or Facts:
Argument/Argument

Valid or Flawed:
Flawed/Flawed

Question Type:
Methods of Reasoning

Stimulus Summary:
M: Qualzan works by the same mechanism as a drug that increases the risk of heart attack, so it probably also increases that risk.

K: True, but they're different chemically, so they probably have different side effects.

Answer Anticipation:
When there is a two-speaker stimulus in a Methods of Reasoning question, it's important to see if the second speaker agrees or disagrees with the premises, and agrees or disagrees with the conclusion. That's not the full consideration, but it is the start.

Here, Kathy agrees with Mark's premise—these two drugs act via the same mechanism. However, she disagrees with his conclusion that they probably have the same side effects. What does she discuss to support this disagreement? A new consideration—the chemical structure of the two drugs being different.

Note that all of these statements are comparative. Mark relies on these two drugs being similar—Kathy brings up a difference. We know comparisons are important on the LSAT, so there's a good chance that comparative language will factor into the correct answer.

So Kathy disagrees with Mark's conclusion stating two things are similar by agreeing with his premise about one similarity but bringing up a separate consideration that highlights a relevant difference.

Answer Explanation:
Analogies count as comparisons, and Kathy does undermine Mark's argument comparing two things as similar by bringing up a relevant difference between them, so this is the correct answer.

Key Takeaway:
Comparative logic is common on the LSAT, so you should note it when it's present as it's likely to factor into the correct answer.