Logical reasoning PrepTest 136 · Section 4 · Question 24

Incorrect. Lives in house → not Own OR not Pay rent
Pay rent . . . and we're out. The stimulus established that a specific case met one of the two necessary conditions, not that it didn't meet it.

Incorrect. Lives in house → not Own OR not Pay rent
Own . . . and we're out. Similar to (A), this answer establishes that one of the necessary conditions isn't met, whereas the stimulus established that one was.

Incorrect. This argument establishes that the neighbors haven't paid rent, not that they don't have to, so there's a key term shift. Maybe the neighbors are behind on rent they have to pay!

Correct. Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Flawed Parallel Reasoning

Stimulus Summary:
Works at Leila's → not Poor performance review OR not Raise
Lester - not Raise
Conclusion - Lester has received a poor performance review

Answer Anticipation:
First, let's discuss the diagram of the first statement using an easier-to-grasp example. If we say that, "No one has both peanut butter and jelly," then we're saying that everyone is missing at least one of them. So everyone is missing either peanut butter or jelly. That's how we ended up with the diagram in the Summary. Also, note that OR is inclusive—it's possible that someone is missing both peanut butter and jelly.

Which is directly related to the flaw in the argument. The premises establish that Lester meets one of the two necessary conditions (he didn't receive a raise), and concludes, therefore, that he doesn't meet the other (he did receive a poor performance review). However, it's possible that someone could meet both conditions of an OR statement (unless it specifically notes "but not both"). We can look for an answer, then, that follows the same conditional structure since the flaw is related to it:
A → not B OR not C
not B
Therefore - C

Answer Explanation:
Lives in house → not Own OR not Pay rent
not Own
Therefore - Pay rent
This argument has the same structure and thus the same flaw as the stimulus. It's possible these neighbors neither own nor pay rent on the house (e.g., a family member owns it and lets them stay for free).

Key Takeaway:
OR statements on the LSAT are inclusive—both conditions could be met—unless they specifically note "but not both."

Incorrect. Live in house AND . . . and we should hop out. This conditional has an AND in the sufficient condition. While the contrapositive of that would put an OR in the necessary condition, we already have an answer that matches, so there's no reason to try to make this answer work.