Logical ReasoningDifficulty: Easy

PT113 S4 Q23 Explanation

Robert: Speed limits on residential

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

TopicsNecessary Assumption

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Stimulus

Robert: Speed limits on residential streets in Crownsbury are routinely ignored by drivers. People crossing those streets are endangered by speeding drivers, yet the city does not have enough police officers to patrol every street. So the city should install presence on residential streets to slow down traffic.

Sheila: That is a bad idea. People who are driving too fast can easily lose control of their hit a speed bump.

What this question is testing

Necessary Assumption

Your task

Find the assumption the argument requires in order for its conclusion to hold.

Common trap

Answers that would help the argument but aren't strictly required (sufficient, not necessary).

Winning move

Negate each choice — the right one breaks the argument when negated.

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

The question
23.

Sheila’s response depends on the presupposition

Answer choices

  1. Trap0% picked this

    problems of the kind that Robert describes are worse in Crownsbury than they are

  2. Trap2% picked this

    Robert’s proposal is intended to address a problem that Robert does not in fact intend

  3. Correct90% picked this

    with speed bumps and warning signs in place, there would still be drivers who would not slow down

    Why this is right

    Answer C is correct.

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

  4. Trap7% picked this

    most of the people who are affected by the problem Robert describes would be harmed by the installation of

  5. Trap0% picked this

    problems of the kind that Robert describes do not occur on any nonresidential

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