Logical reasoning PrepTest 104 · Section 1 · Question 2

Question prompt

Although 90 percent of Remaining source text redacted.
Why the credited answer is right

Credited answer: D

The notes below walk through why it fits the stem and how to eliminate the rest.

Argument or Facts

Argument

Valid or Flawed

Flawed

Question Type

Errors in Reasoning Questions

Stimulus Summary

Only 20% of people understand DNA, so 80% of people can’t make smart medical choices for themselves or society.

Answer Anticipation

Whenever an argument is based on a survey or study, you should start by analyzing that study.
Here, the results aren’t presented in a way that makes us question the sample, as it talks about the population generally. However, it jumps from a survey question about DNA to a conclusion about medical concepts generally. There’s no indication that people who lack knowledge of DNA also lack knowledge about other relevant medical concepts.
The question stem specifically asks us to find an error in reasoning based on what the argument fails to demonstrate. It’s only a flaw to fail to demonstrate something that the argument needs to to work - in other words, it’s a flaw to fail to demonstrate/establish your assumptions. So we’re looking for this Errors in Reasoning answer to be phrased as an assumption of the argument. Let’s find an answer stating that the argument fails to demonstrate that people who lack knowledge of DNA also lack knowledge of other medical concepts.

Answer choices

  1. A
    those people who can Remaining source text redacted.
    Why choice A is not credited
    The premise and conclusion are both about the 80% of people who can’t understand news stories about DNA, so this answer is out of scope.

  2. B
    more than 20 percent Remaining source text redacted.
    Why choice B is not credited
    The argument is about whether people are knowledgeable on topics, not whether people need to be for there to be smart public policy decisions. This answer would be in play if there were another conclusion stating that this lack of knowledge leads to bad policy.

  3. C
    one's being able to Remaining source text redacted.
    Why choice C is not credited
    The stimulus is about people who can’t make well-informed decisions, so this answer about the other group is out of scope.

  4. D
    an understanding of DNA Remaining source text redacted.
    Why choice D matches the stem
    This answer reflects the gap in the argument - that people who don’t understand DNA can’t understand the concepts required for personal or public medical decisions. Since it reflects the argument’s assumption, it’s the correct answer.

  5. E
    since 90 percent of Remaining source text redacted.
    Why choice E is not credited
    People’s self-awareness of the limits of their knowledge isn’t relevant to the conclusion about whether they are limited enough in their knowledge for it to prevent personal or public decisions to be made in a well-informed manner.

What this tests

Question analytics

Based on historical answer selection rates for this question.

Answer choice distribution

  1. A 11%
  2. B 2%
  3. C 2%
  4. D Credited 84%
  5. E 1%

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