LSAT 149 | Section 1 | Logical Reasoning: Q25

LR Question 25 Explanation

QUESTION TEXT: Any popular television series that is groundbreaking…

QUESTION TYPE: Parallel Reasoning

CONCLUSION: Not all popular TV series are groundbreaking.

REASONING: Groundbreaking ➞ critically acclaimed

Contrapositive: not critically acclaimed ➞ not groundbreaking

Some popular TV series are not critically acclaimed.

ANALYSIS: This is a good argument. It uses the contrapositive of a conditional statement to draw the conclusion. The contrapositive looks like this: not critically acclaimed ➞ not groundbreaking

The conclusion is the necessary condition of the contrapositive. So, look for a single statement, its contrapositive, and a conclusion that proves the necessary condition of the contrapositive. You can eliminate two answers for being wrong, and two for being good but not using the contrapositive.

___________

1. This is a good argument, but it doesn’t use the contrapositive.
   Structure: Academic articles ➞ Specialized tech ➞ not widely read
   Conclusion is academic articles are not widely read
2. This is an incorrect reversal.
   Structure: Think improved ➞ high grades
   The conclusion is “think improved”, which is the sufficient condition. We can never conclude the sufficient condition.
3. CORRECT. This works. It uses the contrapositive like the stimulus. Evidence: Unbiased ➞ embarrassing facts. Contrapositive: no embarrassing facts ➞ not unbiased
   The conclusion says “not unbiased”, using “no embarrassing facts.
4. This is a good argument, but like A it merely applies the conditional without the contrapositive. Two answers with identical structure can’t both be right!
   Structure: Person polite ➞ Schwartz polite back
   Colleagues are polite, therefore Schwartz polite.
5. This is an incorrect negation. It negates both sufficient and necessary, without reversing. You can’t do that.
   Structure: Book worth reading ➞ worth buying
   not worth reading ➞ not worth buying

Recap: The question begins with “Any popular television series that is groundbreaking”. It is a Parallel Reasoning question. Learn how to master LSAT Parallel questions on the LSAT Logical Reasoning question types page.