Logical ReasoningDifficulty: Easy

PT143 S4 Q9 Explanation

In a sample containing 1,000 peanuts

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

TopicsParallel

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Stimulus

In a sample containing 1,000 peanuts from lot A and 1,000 peanuts from lot B, 50 of the peanuts from lot A were found to be infected with Aspergillus. Two hundred of the peanuts from lot B were found to be infected more widespread in lot B than in lot A.

What this question is testing

Parallel

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
9.

The reasoning in which one of the following is most similar to the reasoning in

Answer choices

  1. Wrong Validity1% picked this

    Every one of these varied machine parts is of uniformly high quality. Therefore, the machine that we assemble from them will

    This argument reasons that what is true of each part is true of the whole. This is a common flawed method of reasoning and does not match the validity of the argument in the stimulus.

  2. Wrong Reasoning0% picked this

    If a plant is carelessly treated, it is likely to develop blight. If a plant develops blight, it is likely to die. Therefore, if

    While this is a valid argument, it relies on a different reasoning structure than the argument in the stimulus. This argument rests on conditional logic, while that in the stimulus rests on comparative reasoning.

  3. Wrong Reasoning / Wrong Validity1% picked this

    In the past 1,000 experiments, whenever an experimental fungicide was applied to coffee plants infected with coffee rust, the infection disappeared. The coffee rust

    This argument mistakes correlation for causation. Not only does this argument rest on different reasoning than the stimulus, it also has the wrong validity.

  4. Correct98% picked this

    Three thousand registered voters—1,500 members of the Liberal party and 1,500 members of the Conservative party—were asked which mayoral candidate they favored. Four hundred

    Why this is right

    This argument reaches a conclusion that compares the popularity of a political candidate between two groups. It reaches its conclusion by

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

  5. Wrong Reasoning0% picked this

    All of my livestock are registered with the regional authority. None of the livestock registered with the regional authority are free-range livestock. Therefore, none

    This argument rests on conditional logic, while the argument in the stimulus rests on comparative reasoning.

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