Logical Reasoning · Flaw
PrepTest 133 · Section 3 · Question 2
Phase 1 (your first ~400 questions): read the guidance, then answer. No clock.
Step 1 · Pre-Question Guidance · read this first
- “almost everyone”
- “just about”
- “after all”
Playground logic
Marcus says nearly every kid in town dreams of chess trophies, because all his chess club pals do. The patty is a sample of his own club; the top bun is about the whole town. That is a Weird Sample: his friends were never a fair mirror of everyone.
Step 2 · The kid story
Marcus Polls the Chess Club
Marcus burst into the lunchroom. "Big news! Almost every kid in this whole town secretly wants to be a chess champion!" Nadia raised an eyebrow. "How do you know?" "Easy. I asked everybody I know. Every single one of them said they dream of winning a chess trophy someday, even if right now they mostly play checkers." Owen leaned over. "Marcus, where do you spend every afternoon?" "Chess club, obviously." "And who are the people you know?" Marcus paused. "Chess club people." Priya set down her juice box. "So you asked a room full of chess fans whether they like chess, and then talked about the whole town." Marcus frowned at his notebook. "When you say it like that, it sounds less amazing."
Step 3 · Try the model question
Marcus: Almost every kid in town wants to be a chess champion. After all, nearly everyone I know dreams of winning a chess trophy, even the ones who mostly play checkers now.
Which choice best describes the mistake in Marcus's reasoning?
Step 4 · The courtroom tale
The Kite Lover's Survey
A kite shop owner, Mr. Pell, wanted the city to build a giant kite field. He told the judge, "Nearly every resident wants one. I asked everyone I know." Mr. Whitfield stood, suspenders creaking. "Your Honor, where did Mr. Pell do his asking?" "At my shop," said Mr. Pell, "and at the kite festival." Mr. Whitfield turned to the jury. "So he asked kite buyers and kite flyers whether they love kites. Shocking result: they do." The judge sighed. "Mr. Pell, your friends may be lovely, but they are not the whole city." Mr. Pell clutched his kite string sadly.
Step 5 · Work the real question
Open PrepTest 133, Section 3, Question 2 in your official copy from LSAC (for example in LawHub) and read it there.
Your answer
How to apply it
Find the conclusion and note exactly which group it covers. Then find the evidence and ask who was actually checked. If the checked people were picked through the speaker's own circle or a setting that makes them special, the sample does not mirror the larger group. Choose the answer that names this mismatch between the sample and the whole, and set aside answers naming flaws the argument never commits.