LSAT 124 | Section 2 | Logical Reasoning: Q20

LR Question 20 Explanation

QUESTION TEXT: On some hot days the smog in Hillview reaches unsafe levels…

QUESTION TYPE: Flawed Reasoning

CONCLUSION: On some days in Hillview, wind blows from the east and smog reaches unsafe levels.

REASONING: On some days in Hillview, the wind blows from the east. And, on some days in Hillview, smog reaches unsafe levels.

ANALYSIS: Let’s attempt an analogy to see the problem.

• Take the statement: “On some days in New York, it snows.”
• And then: “And on some days in New York, it is uncomfortably warm outside.”

Now, what if I were to conclude: “Therefore, on some days in New York, it is snowing and uncomfortably warm outside.” Does that make sense? No. You can’t draw a conclusion from two “some” statements.

___________

1. This is a different error. An example of this error would be: “sometimes sunny days are warm; therefore warm days are necessarily sunny.” We don’t actually know if the two conditions ever occur together.
2. CORRECT. This answer choice might win a prize for “most abstract wording,” but it’s correct. The sets are “smoggy days,” “east windy days,” and “Hillview.” Sometimes Hillview coincides with “smoggy,” sometimes, “east windy.” But we have no idea if all three of these “sets” ever coincide (occur at the same time).
3. “Rare steak” and “rare diamonds” would be an example of this mistake. Here, unsafe is never given a specific definition, and seems to be used in the same sense both times.
4. It’s quite plausible that Hillview is sometimes smoggy or windy, whether or not the conclusion is true.
5. We don’t actually know if there is a correlation; that’s what the conclusion is trying to prove (that smog and wind occur together).

Recap: The question begins with “On some hot days the smog in Hillview reaches unsafe levels”. It is a Flawed Reasoning question. Learn more about LSAT Flaw questions in our guide to LSAT Logical Reasoning question types.