Logical ReasoningDifficulty: Hard

PT103 S1 Q21 Explanation

Not all tenured faculty are full

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

TopicsParallel Flaw

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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

Not all tenured faculty are full professors. Therefore, although every faculty member in the linguistics department has tenure, it must be the case that not all of linguistics department are full professors.

What this question is testing

Parallel Flaw

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
21.

The flawed pattern of reasoning exhibited by the argument above is most similar to that exhibited by which

Answer choices

  1. Weak Premise Match25% picked this

    Although all modern office towers are climate- controlled buildings, not all office buildings are climate-controlled. Therefore, it must be the case that not all

    The outcome (right side) of the conditional premise should show up again in the 2nd premise as the same idea (not as the negated version of the idea). And it should be the subject of the 2nd premise, not the backend. Original Argument This Argument Premise 1: All A's are B All MOT's are C. Premise 2: Some B's are ~C Some OB's are ~C. Conclusion: Some A's are ~C Some OB's are ~MOT.

  2. Weak Premise Match5% picked this

    All municipal hospital buildings are massive, but not all municipal hospital buildings are forbidding in appearance. Therefore, massive buildings need

    The outcome (right side) of the conditional premise should show up again in the 2nd premise as the subject of the 2nd premise. Original Argument This Argument Premise 1: All A's are B All MHB's are M. Premise 2: Some B's are ~C Some MHB's are ~F. Conclusion: Some A's are ~C Some M's are ~F.

  3. Correct58% picked this

    Although some buildings designed by famous architects are not well proportioned, all government buildings are designed by famous architects. Therefore, some government

    Why this is right

    Original Argument This Argument Premise 1: All A's are B All GB's are DFA. Premise 2: Some B's are ~C Some DFAs are ~WP. Conclusion: Some A's are ~C Some GB's are ~WP.

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

  4. Bad Premise Match8% picked this

    Not all public buildings are well designed, but some poorly designed public buildings were originally intended for private use. Therefore, the poorly designed public

    The two premises are Some / Not All statements, and the conclusion is an All. We wanted an All in the premise and a Some / Not All conclusion, so this one isn't worth digging into.

  5. Weak Premise Match4% picked this

    Although some cathedrals are not built of stone, every cathedral is impressive. Therefore, buildings can be impressive even though they

    The outcome (right side) of the conditional premise should show up again in the 2nd premise as the subject of the 2nd premise. Original Argument This Argument Premise 1: All A's are B All C's are I. Premise 2: Some B's are ~C Some C's are ~BS. Conclusion: Some A's are ~C Some I are ~BS.

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