LSAT 142 | Section 4 | Logical Reasoning: Q25

LR Question 25 Explanation

QUESTION TEXT: Of the citizens who disapprove of the prime minister’s…

QUESTION TYPE: Flawed Parallel Reasoning

CONCLUSION: If you dislike the Prime Minister, it’s probably because you dislike her plan to raise income tax.

REASONING: Teresa wants the income tax to be raised. So she probably likes the Prime Minister.

ANALYSIS: This is a bad argument. People are complicated, and our political opinions don’t all fall in a line. Theresa might like income tax increases, but dislike the Prime Minister for some other reason.

The argument incorrectly tries to take the contrapositive of this “most” statement:

Dislike PM (most) ➞ dislike income tax plan

The argument reverses and negates the terms above. This doesn’t work for “most” statements the way it does for normal conditional statements. “Most” people who dislike the Prime Minister do so because of taxes, but some people, like Theresa, might dislike the PM for other reasons.

The wrong answers fit into two groups. B and C say that the person in question fails to match the left side of the “most” statement. But in the stimulus, Theresa failed to match the right side of the “most” statement.

D and E are good arguments. “Most” is the same as “probably”. If most cats are black, then it’s correct to say that an individual cat is “probably” black. If we know nothing else about the cat, then the general “most” statement applies directly. So if 54% of cats are black, then an individual cat has a 54% chance of being black. Both D and E correctly apply individual cases to “most” statements in this way.

___________

1. CORRECT. This matches. There is a “most” statement, and the argument incorrectly tries to take the contrapositive of that statement:
   Support logging (most)➞ believe in risk of firesAndy doesn’t believe in the risk of fires, but that doesn’t mean he supports logging. We only know that most people who support logging believe in fires. But some people, like Andy, might support logging for other reasons.
2. This doesn’t work. In the stimulus, Theresa wasn’t part of the right hand side of the “most” statement. Here, Bonnie isn’t part of the left hand side of the “most” statement (expecting population to increase over the next ten years).
3. Same as B. In the stimulus, Theresa wasn’t part of the right hand side of the “most” statement. Here, Chung isn’t part of the left hand side of the most statement (believing the economy improved).
4. This is a good argument.
   Oppose Loffoch Valley light rail feasibility study (most)➞ support valley freeway.
   This correctly applies Donna’s situation to the “most” statement. Donna opposes the study, so it’s true to say that she probably supports the freeway.
5. This is a good argument.
   Believe blizzard tomorrow (most)➞ Channel 9 news
   Eddies believes there will be a blizzard, so it’s correct to apply the “most” statement to him and say he probably saw the news report.