PrepTest 125

[lcid:3599] Prep Test 125 LSAT — Logical Reasoning — S4 Logical reasoning

Question prompt

Politician: The current crisis Remaining source text redacted.
Why the credited answer is right

Credited answer: B

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 students spend a Remaining source text redacted.
    Why choice A is not credited
    Incorrect. This statement reverses the chain. The sufficient condition here is the necessary condition of the chain.
  2. B
    The current crisis in Remaining source text redacted.
    Why choice B matches the stem
    Correct. Argument or Facts:
    Facts

    Question Type:
    Must Be True

    Stimulus Summary:
    Remain competitive globally → Overcome math education crisis
    Overcome math education crisis → Successful teaching methods
    Successful teaching methods → Get students to study outside of class

    Answer Anticipation:
    This Must Be True question features a lot of conditional logic ("if", "requires", "No"), so we should make sure we understand the diagram.

    The first sentence is a relatively straightforward "if" statement. The second brings up what is "require[d]" for alleviating a crisis—that requirement is a necessary condition.

    And the final statement is a "No" statement, which can be a little complex to diagram. Saying "No As are B" is the same as saying "If you are A, then you are not B." The double negatives there can get a bit tricky, so we'd recommend reading the sentence in the stimulus back-to-back with your conditional to make sure they mean the same thing.

    With everything diagrammed, we can see that these statements all chain together, so we should write that out, take the contrapositive, and then find an answer that aligns with the chain:
    Remain competitive globally → Overcome math edu crisis → Successful teaching methods → Get students studying outside class

    not Get students studying outside class → not Successful teaching methods → not Overcome math edu crisis → not Remain competitive globally

    Answer Explanation:
    not Get students studying outside of class → not Overcome math edu crisis. This answer matches a portion of the contrapositive, so it's the correct answer.

    Key Takeaway:
    When you see conditionals in a Must Be True question, start diagramming immediately! The faster you get those statements diagrammed (and chained and contraposed, if relevant), the faster you'll get to the correct answer.
  3. C
    Few subjects are as Remaining source text redacted.
    Why choice C is not credited
    Incorrect. The stimulus doesn't discuss other subjects or their importance, so this answer is out of scope.
  4. D
    Only if we succeed Remaining source text redacted.
    Why choice D is not credited
    Incorrect. Remaining competitive is a necessary condition in this answer ("Only if"), so we can immediately eliminate it since that term is a sufficient condition of the conditional chain.
  5. E
    Students' spending a significant Remaining source text redacted.
    Why choice E is not credited
    Incorrect. This answer is causal ("would help us"), whereas the stimulus is conditional. Even without that issue, the argument is a reversal of the conditional chain.

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