PrepTest 126

Correct. Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Weaken

Stimulus Summary:
Carl has solved a lower percentage of cases than any other detective, so he's incompetent.

Answer Anticipation:
When dealing with a Weaken question, it's important to figure out the flaw/assumption in the argument—the correct answer will present evidence that it's a bad assumption, or point out the flaw. And there's one element to this stimulus that suggests a flaw that isn't present here, and there's one element that suggests a flaw that is.

The element that suggests a flaw that isn't present is that it talks percentages. Frequently, the LSAT will jump between percentages and amounts—an invalid jump. However, in this case, the premise presents both a percentage and an amount—1 out of 25 tells us how many cases Carl has solved as well as the percentage of cases. Since we have both a percentage and an amount, the argument can't illicitly jump between the two.

The element that suggests a flaw that is present is the comparison—Carl has solved a smaller percentage of cases than his peers. Comparison flaws have a few different types, and two are present here.

First, the argument jumps between comparative and absolute considerations. The premise is that Carl has solved fewer cases compared to the other detectives. That might support Carl as less competent than those other detectives, but that's not enough to say he's incompetent. Maybe the entire department is competent, and 1/25 isn't a bad solve rate, but it's just not as good as others. In jumping from a relative premise to an absolute conclusion, this argument is flawed. It can therefore be weakened by highlighting how Carl's solve rate is still good even if not as good as others.

Second, the argument compares Carl's solve rate to other detectives, but there's no indication that the cases they solved are comparable. If Carl only takes on the hardest cases, then solving any of them might be a great demonstration of competence. In failing to make an apples—to—apples comparison, this argument is also flawed, and any answer highlighting a difference in the cases between Carl and other detectives should be considered.

Answer Explanation:
This answer highlights a difference between Carl and the other detectives that would naturally lead to his solve rate being lower, despite him not lacking competence. Since the argument relies on the cases assigned to the detectives being similar in order to use them as a basis for comparison, this answer highlighting a difference between the cases weakens the argument.

Key Takeaway:
Arguments that rely on comparisons frequently have answers that also address comparisons. When an argument relies on similarities, differences usually weaken it.

Incorrect. Respect as a police officer doesn't address competence as a detective. This answer is trying to get you to think that the positive response of the residents somehow translates to his work as a detective, but that's a jump and so this answer is out of scope.

Incorrect. If anything, this suggests that Carl should be able to solve more crimes, thus aligning with the argument.

Incorrect. This answer provides more examples of Carl failing to solve crimes, thus strengthening the argument (if anything).

Incorrect. This answer is about officers, not detectives, so it's out of scope.