PrepTest 143

[lcid:3668] Prep Test 143 LSAT — Logical Reasoning — S1 Logical reasoning

Question prompt

Dr. Khan: Professor Burns Remaining source text redacted.
Why the credited answer is right

Credited answer: C

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

Question Type

Must Be True Questions

Answer choices

  1. A
    If the recent observations Remaining source text redacted.
    Why choice A is not credited
    Incorrect. It's rare that a Must Be True question will have a hypothetical answer ("If the recent observations had been made . . . "), and this question isn't an exception. There's no information that would justify a conclusion about what would have happened in a separate case.
  2. B
    Contrary to Professor Burns's Remaining source text redacted.
    Why choice B is not credited
    Incorrect. This answer is too strong. While the recent observations don't prove the initial ones are false, they aren't shown to actually prove the initial ones, either. Selecting this answer would see you falling for an absence of evidence flaw.
  3. C
    Professor Burns's claim about Remaining source text redacted.
    Why choice C matches the stem
    Correct. Argument or Facts:
    Facts

    Question Type:
    Must Be True

    Stimulus Summary:
    Earlier reports Ð There's a comet reservoir out in our solar system
    New reports Ð Fail to confirm this
    Prof. Burns's conclusion Ð Earlier reports are wrong
    Rebuttal Ð The new reports were under poor conditions

    Answer Anticipation:
    While this is a Must Be True question, the stimulus has all the hallmarks of a full argument. We are given background (the earlier reports and the new ones), an opposing point (Prof. Burns), and a pivot to rebuttal evidence. The only thing we're missing is Dr. Khan's conclusion!

    Here, it's clear that he believes Prof. Burns is basing her conclusion on evidence that isn't strong enough to support it. He pivots ("But") and calls the strength of the evidence into question. While normally we shouldn't draw a conclusion from this, the question asks us to find an answer that's only "most supported" by the stimulus—a bit weaker than the normal question. As such, the correct answer will probably reflect Khan's strongly implied belief that Burns's conclusion isn't warranted by the recent evidence.

    Answer Explanation:
    While Dr. Khan never directly states that Prof. Burns is incorrect, he brings up the poor conditions as part of a rebuttal ("But . . . ") to her claims, thus supporting that he believes she's incorrect. While this answer normally wouldn't fly, this is a "most supported" question—a rare Must Be True variation where the bar to a correct answer is a little lower.

    Key Takeaway:
    Normally, we shouldn't read a conclusion into an argument where one isn't written. However, when a viewpoint is rebutted by the author of an argument ("But . . . "), it's implied that the author disagrees with that viewpoint in some key way. We've seen this play out in Point at Issue questions before, and now we've seen it in a Must Be True question, albeit a "most supported" one.
  4. D
    The recent observations, even Remaining source text redacted.
    Why choice D is not credited
    Incorrect. There's no way to know what would have happened under good conditions.
  5. E
    The poor conditions present Remaining source text redacted.
    Why choice E is not credited
    Incorrect. This answer is too extreme in calling those results "worthless"—while Dr. Khan may discount their value, he may believe there is some value to them.

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