PrepTest 143

Incorrect. There's no equivalent "Every" statement in the stimulus, so we can rule this answer out. (It's also flawed in a different way—it has a part-to-whole flaw.)

Incorrect. This answer doesn't feature a sample, instead featuring quantified (likely = most) statements. It's also flawed in a different way—two most statements can't be combined in this manner.

Incorrect. Be careful of answers that throw something like a matching number at you—they're likely wrong, but they're trying to get people to bite on that matching number! This answer jumps from a correlation to causation, thus committing a different flaw.

Correct. Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Parallel Reasoning

Stimulus Summary:
Lot A – Of 1,000 peanuts, 50 were infected
Lot B – Of 1,000 peanuts, 200 were infected
Therefore: More of lot B is infected than lot A

Answer Anticipation:
This argument relies on a sample to draw a conclusion about the relative prevalence of something between those groups. We know that samples and comparisons are frequently tested on the LSAT, so those elements are likely to be repeated in the correct answer.

(Also, not necessarily important to note, but samples should always make you think of a sampling flaw. Here, the samples are pretty large—though the lots might be millions of peanuts, so maybe not—but there's no indication that they're representative or random, so there is a slight sampling flaw here. The correct answer should similarly fail to establish that the samples are representative/random.)

Answer Explanation:
This answer features an argument where a sample is used to draw a comparative conclusion between the groups, so it's parallel to the stimulus.

Key Takeaway:
Many Parallel Reasoning questions are based in conditional logic, and matching up those elements will allow you to find the correct answer. However, any commonly tested feature of an argument (related to logic) that shows up in these questions can be identified as something that should match in the correct answer. If anything is familiar to you from other questions on the exam, note it to help you find the correct answer.

Incorrect. This argument chains two conditionals together to form a valid conclusion, none of which is true of the stimulus.