Logical ReasoningDifficulty: Medium

PT101 S2 Q11 Explanation

Not surprisingly, there are no

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

TopicsMust be True

Keep going in LSAT Lab

  • Save & drill this skill — build targeted practice sets from questions like this one

  • Video walkthroughs — watch every question solved step by step

  • 81 official LSATs — as questions, timed sections & full-length tests

Start practicing free

Free to start

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 surprisingly, there are no professors under the age of eighteen. And, as well known, no one under eighteen can vote legally. Finally, some brilliant people are and some are under eighteen.

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
11.

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

Answer choices

  1. Potentially Contradicted4% picked this

    No professors are

    One of our inferences allows for brilliant, 18-year old professors. - some people are brilliant, professors, and 18+ - some people are brilliant, legal voters, and 18+ - some people are brilliant, under 18, not professors, and not legal voters No professors are under the age of 18, but that doesn't mean no professors are age 18.

  2. Too Strong: all3% picked this

    All brilliant people are either professors, legal voters, or

    We can't say anything about all brilliant people, because the passage didn't ever tell us something that was true about all brilliant people. It's possible that there's a brilliant person who isn't a professor, isn't a legal voter (maybe he's a felon or just never registered to vote), and is 18 or older.

  3. Unsupported Overlap16% picked this

    Some legal voters are not

    Did we ever derive that "legal voter" and "not professor" were found in the same person? - some people are brilliant, professors, and 18+ - some people are brilliant, legal voters, and 18+ - some people are brilliant, under 18, not professors, and not legal voters Nope. We know that some brilliant people are legal voters and that some brilliant people are not professors, but we don't have any way to prove those are the same people.

  4. Out of Scope: not brilliant3% picked this

    Some professors are neither legal voters nor

    The passage provided zero information about people who are not brilliant.

  5. Correct74% picked this

    Some brilliant people are neither professors nor

    Why this is right

    Did we ever derive that "brilliant" and "not professor" and "not voter" were found in the same person? - some people are brilliant, professors, and 18+ - some people are brilliant, legal voters, and 18+ - some people are brilliant, under 18, not professors, and not legal voters Yes, that's our final line. We know some brilliant people are under 18, which proves they are not professors and not legal voters.

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

Continue the review in LSAT Lab

Save this question, watch the video walkthrough, and drill similar questions in your LSAT Lab account.

Save and practice this skill
LSAT Lab

Turn this review into a targeted study plan.

Save this question, drill more like it, watch the video walkthrough, and track your progress in your LSAT Lab account.

Start practicing free