Logical ReasoningDifficulty: Hard

PT156 S2 Q17 ExplanationTo measure a small boat hull accurately

A free, expert breakdown of this official LSAT Logical Reasoning question.

TopicsMust be True

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Full official LSAT questions are available through LawHub. This page provides LSAT Lab's explanation, strategy, and review tools without republishing the full official question.

Stimulus

To measure a small boat hull accurately, it is necessary to level the hull so that a baseline can be established. This does not require sophisticated tools, but it does require a leveling tool called a "line level." When scientists discovered a small ninth-century boat, they wanted to record the dimensions of were not sure they had leveled the hull before establishing a baseline.

What this question is testing

Must be True

Your task

Break the argument into its conclusion and evidence, then do exactly what the question stem asks with that structure.

Common trap

Answers that sound relevant to the topic but don't connect to the argument's actual reasoning.

Winning move

Predict what a right answer must do, then test each choice against the conclusion-evidence gap.

Reading along? Open the full official question in LawHub — we show a fragment here and keep the reasoning in our own words.

The question
17.

If the statements above are true, then which one of the following must

Answer choices, explained

  1. Trap7% picked this

    The scientists did not accurately measure the hull's dimensions because they had no

  2. Trap10% picked this

    The scientists accurately determined the hull's dimensions, provided that they leveled

  3. Trap16% picked this

    If the scientists did not accurately determine the hull's dimensions, it was because they did not

  4. Correct63% picked this

    The scientists were able to accurately record the hull's dimensions only if they used

    Why this is right

    Answer D is correct.

    Skill tested: Must be True · how this choice captures the argument's function is the move to repeat next time.

  5. Trap4% picked this

    If the scientists had measured the hull's dimensions accurately, then at least one of them would have

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