LSAT 151 | Section 4 | Logical Reasoning: Q15

LR Question 15 Explanation

QUESTION TEXT: Columnist: Many car manufacturers trumpet their cars’…

QUESTION TYPE: Flawed Reasoning

CONCLUSION: Manufacturers likely inflate their fuel efficiency figures.

REASONING:

1. “Many” manufacturers advertise fuel economy under regular driving conditions.
2. I have tried three cars, and haven’t been able to get this fuel economy.

ANALYSIS: There are many, many car manufacturers and car types available for purchase. Driving three cars is not a good way of testing the fuel economy of the car market as a whole.

It’s rare for flaw questions to actually have sample size errors, but this is a fairly clearcut case: three is not enough. You should avoid picking sample size error as an answer unless the sample is specifically small the way this one is.

___________

1. CORRECT. See the analysis above. There are hundreds (thousands?) of types of cars available for purchase. The columnist tried….three. They may have just gotten unlucky.
2. For something to be a flaw, the author has to actually say it. The author did not say this. In fact, this statement is so insane that no one would ever say it. You have to take LSAT statements literally, and this one literally means “I expect driving to be the same in the Alaskan tundra and the Arizonan desert”.
    
   To be clear: I’m not saying you are insane for picking this. You surely gave the sentence a reasonable interpretation, like “maybe the driver drove in tough conditions and didn’t think about how the fuel economy would be better in normal conditions.”.
    
   That is an extremely reasonable response to this argument. But, it isn’t what this answer said, and you have to be very careful not to twist an answer from something insane into something reasonable, in order to help prove it right. The answers are, by and large, wrong, and it isn’t your job to help them be right.
    
   Get in the habit of interpreting statements literally. If a statement’s literal meaning is insane, it’s unlikely the argument said it.
3. The author was saying that manufactures are unreliable. They’re the only “source of a claim” in the argument. So the author definitely didn’t overlook the possibility that manufacturers were unreliable!
4. The author did presume that manufactures lie, but he didn’t do it without justification. His justification was that his cars didn’t meet the advertised fuel efficiency. His justification was weak due to small sample size, but definitely had some evidence rather than none.
5. This didn’t happen. “Two different senses” means two really different word uses. It’s actually pretty hard to use fuel economy in different senses: it only has one definition.
    
   Example of flaw: One friend said he’s seeing Cats the musical. My other friend said she’s going to buy cats at a pet store. I didn’t know you could buy a musical!