Logical Reasoning · Weaken

PrepTest 103 · Section 2 · Question 12

Phase 1 (your first ~400 questions): read the guidance, then answer. No clock.

Step 1 · Pre-Question Guidance · read this first

Question type

Weaken

The one idea it tests

When two things rise and fall together across groups, a third factor that rides along with one of them can be the real cause.

The basic logic

Evidence: across groups, more of X goes with more of Y. Conclusion: each individual should change X to change Y. That is a Rooster move. Pop it by showing something else travels with X and could be driving Y.

Tiny words that decide it

“the higher”
“the lower”
“so”
“should”

Playground logic

Kevin says classes with more recess get higher spelling scores, so each kid should take more recess to spell better. The patty is a group pattern; the top bun is advice to individuals. Show that the extra-recess classes also have the reading tutor, and the burger falls apart.

Step 2 · The kid story

Recess Makes Spellers?

Kevin had a chart, and he was thrilled. "Look! The classes with the most recess have the best spelling scores. The classes with the least recess have the worst. So if I want to ace spelling, I should take more recess!" He was already holding a dinosaur ball. Lulu flipped her clipboard. "Wait. Which classes get extra recess?" Priya checked the schedule. "The same classes that share Ms. Patel, the reading tutor. She visits them every morning." Lulu nodded. "So maybe the tutor makes the spellers, and recess is just tagging along." Kevin looked at his ball, then at his spelling list. "So recess might be a rooster that crowed when the sun came up anyway?" "Exactly," said Priya.

Step 3 · Try the model question

Kevin: The more recess a class gets, the higher its average spelling score; the less recess, the lower its score. So any student who wants to spell better should spend more time at recess.

Suppose each choice below were true. Which one hurts Kevin's reasoning the most?

Step 4 · The courtroom tale

The Case of the Lucky Socks

A sock company was sued for false advertising. Its ads said: "Teams that wear more of our socks win more games. Want to win? Buy our socks!" Mr. Whitfield, for the shoppers, called a coach to the stand. "Coach, which teams buy the most of these socks?" "The teams with the biggest budgets." "And do those teams also have full-time trainers and new gear?" "All of them do." Mr. Whitfield turned to the jury. "Money buys the socks, and money buys the trainers. The trainers might be winning the games, while the socks just ride along." The judge wrote a note. The sock company's lawyer looked down at his own socks, which did not seem to be helping him.

Step 5 · Work the real question

Open PrepTest 103, Section 2, Question 12 in your official copy from LSAC (for example in LawHub) and read it there.

Your answer

How to apply it

Spot the pattern: a group-level link between two things, then advice for individuals. Name the gap: the link could come from a third factor. Scan for the choice that shows something else moves together with the suspected cause and could produce the effect. Pass over choices that offer exceptions, explain why the cause varies without touching the effect, or simply restate that the effect matters.