Logical reasoning PrepTest 132 · Section 2 · Question 23

Incorrect. The stimulus discusses the danger to those who are consuming higher amounts of TMD, not possible negative health effects for those who are consuming low amounts.

Incorrect. It's noted that 80% of the population doesn't eat peaches, and so from the information we have it can't be concluded that most of the population is likely to ingest TMD.

Correct. Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Principle (Strengthen)

Stimulus Summary:
80% of people don't have enough TMD to be in danger, but some of the other 20% do. Therefore, it's not an acceptable practice.

Answer Anticipation:
Principle (Strengthen) questions have answers that connect the judgment in the conclusion to the details in the scenario/premises. Here, the conclusion is that using this pesticide TMD isn't an acceptable practice, so that's what the correct answer has to justify.

Why isn't it an acceptable practice? Because while a majority of people aren't affected by it, a subset of the population ingests enough of a pesticide for it to potentially be a danger to them. The correct answer, therefore, should connect these ideas:

If a subset of a population is potentially endangered by a practice, then that practice is unacceptable.

Harder Principle (Strengthen) questions—like one that shows up as a question #23—are likely to have more abstract answers, or answers that don't 100% justify the conclusion, or have some other means of making the correct answer harder to spot, so let's stay flexible.

Answer Explanation:
This answer talks about acceptability—the key judgment in the conclusion—so we should fully consider it. The conclusion is that something is unacceptable, but this answer sets out two necessary conditions for something to be acceptable, so the contrapositive will justify the relevant conclusion:

Acceptable → Used as intended AND Shown not to harm anyone
not Used as intended OR not Shown not to harm anyone → not Acceptable

The pesticide is being used as intended, but it hasn't been shown not to harm people who ingest a lot of peaches. That's enough to trigger this principle, allowing the conclusion that the practice is not acceptable to be drawn, so this is our answer.

Key Takeaway:
The correct answer here pulled two tricks to make it harder to spot. First, it gave us the contrapositive of the principle that aligns with the structure of the argument. Second, it threw in an extra (and ultimately extraneous, since it was part of an OR sufficient condition) term. For the latter, note that it threw it in before the relevant term, thus hoping you'd eliminate the answer before reading the good part. For Principle (Strengthen) questions, always read an answer that brings up the judgment in the conclusion in its entirety.

Incorrect. Average doses from the population are low and have been shown to have no effect on human health, so this answer doesn't apply to the stimulus.

Incorrect. The stimulus hasn't noted that the pesticide is used to protect the population from harm—it may be to preserve peach profits.