LSAT 144 | Section 4 | Logical Reasoning: Q6

LR Question 6 Explanation

QUESTION TEXT: If one is to participate in the regional band, one must…

QUESTION TYPE: Flawed Parallel Reasoning

CONCLUSION: Lily doesn’t practice hard.

REASONING: Regional band ➞ practice OR talented

Lily is talented.

ANALYSIS: This argument messes up “or”. We have two necessary conditions for being in the regional band: talent, or practice. And you only need one, since it’s an “or” statement.

So far, so good. But on the LSAT, “or” is inclusive. That means you can have both items in an “or” statement. So to be in the band, you can be talented, practice hard, or both.

To parallel this argument, look for an answer with a single conditional, and two necessary conditions joined by an “or”. Then the conclusion will be “they have one, so they don’t have the other”.

___________

1. This only has individual necessary conditions: Objectives ➞ mobility ➞ good weather
2. Two problems:
   1. This negates the sufficient. The stimulus didn’t do that.
   2. Toronto and Chicago are exclusive. You can’t be in two cities at once.
   Premise: Vacation ➞ Toronto OR Chicago
3. This argument makes a different flaw. The author goes backwards from sufficient to necessary. That’s not what the stimulus did.
   Premise: Johnson win ➞ Horan AND Jacobs
4. CORRECT. This matches exactly. There’s one conditional statement with two necessary conditions, joined by an “OR”. The author incorrectly thinks the two terms are exclusive, and so concludes that because Julie has one, she can’t have the other.
   Premise: Informed ➞ newspaper OR TV
   Conclusion: Informed and newspaper ➞ TV
5. This argument skips a step. It would have been right if it said “Wayne is going to get a ride home, and Yvette isn’t at the Library”. But this doesn’t match the stimulus.