Logical ReasoningDifficulty: Easy

PT124 S3 Q4 Explanation

A recent test of an electric

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

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Stimulus

A recent test of an electric insect control device discovered that, of the more than 300 insects killed during one 24-hour period, only 12 were mosquitoes. Thus this type of device may kill many in controlling the potentially dangerous mosquito population.

What this question is testing

Weaken

Your task

Find the choice that makes the argument's conclusion less likely to be true.

Common trap

Answers that look negative but attack a claim the argument never relied on.

Winning move

Find the assumption the argument depends on, then pick the choice that undermines it.

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

The question
4.

Which one of the following, if true, most seriously weakens

Answer choices

  1. Correct82% picked this

    A careful search discovered no live mosquitoes in the vicinity of the device

    Why this is right

    This suggests the device killed 100 percent of the mosquitoes in the area. That would weaken the claim that the device will not significantly control the mosquito population.

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

  2. Out of Scope - Other Group7% picked this

    A very large proportion of the insects that were attracted to the device

    This is not relevant to whether the device will control the mosquito population.

  3. Out of Scope1% picked this

    The device is more likely to kill beneficial insects than it is to

    The issue isn’t whether the device should be put to use, but whether it would be effective at controlling the mosquito population.

  4. Strengthens9% picked this

    Many of the insects that were killed by the device are

    This make it less likely that the device will control the mosquito population since it kills a natural predator of mosquitoes.

  5. Too Weak1% picked this

    The device does not succeed in killing all of the insects

    The device could still be effective at controlling the mosquito population since it could be that only insects other mosquito's were able to get away from the device and survive once attracted to it.

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