Logical Reasoning · Flaw

PrepTest 134 · 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

Question type

Flaw (Principle Application)

The one idea it tests

A rule that needs someone to know something was applied to someone who only guessed.

The basic logic

Read the rule's trigger carefully, word by word. Then check whether the story actually meets each part of the trigger. If the rule needs knowing and the person only claimed without checking, the application skips a condition.

Tiny words that decide it

“if”
“know”
“thereby”
“therefore”

Playground logic

The class rule says you fib only if you report something you know is untrue. Owen reported something without checking, and it turned out wrong. Marcus calls that a fib, but the rule's patty needs knowing, and Owen only guessed: a guess is not the same as a known falsehood.

Step 2 · The kid story

Owen and the Homework Report

Ms. Rivera has a class rule: "If you tell me a classmate finished their homework while you know they did not, you are fibbing." One morning Ms. Rivera asked Owen whether Kevin had finished his math sheet. Owen had not looked. He shrugged and said, "Yep, it's done." It was not done. Kevin had drawn a stegosaurus on it instead. Marcus pulled out his magnifying glass. "Case closed! Owen fibbed. That's the rule!" Priya set down her juice box. "Wait. The rule says you have to know it is not done. Owen didn't know anything. He just didn't check." Lulu wrote on her clipboard: "careless is not the same as knowing." Owen still promised to check next time, and Kevin promised to do the math before the dinosaurs.

Step 3 · Try the model question

Class rule: if you tell the teacher a classmate finished their homework while you know they did not, you are fibbing. Owen told the teacher that Kevin's homework was done without ever looking at it. Kevin's homework was not done. So Owen was fibbing.

Which choice points to the weakest spot in how the rule was applied?

Step 4 · The courtroom tale

The Case of the Confident Weather Guess

A town law said: "Anyone who announces that the pond is safe for skating, knowing the ice is thin, is guilty of a false warning." A park helper announced the pond was safe. He had never tested the ice. It was thin. The prosecutor pounded the table. "Guilty! He called it safe, and it wasn't!" Mr. Whitfield adjusted his suspenders. "Your Honor, the law requires knowing the ice is thin. My client knew nothing. He was careless, perhaps, but the law punishes knowing, not guessing." The judge sighed. "Carelessness may deserve a different law. This one needs knowledge, and the prosecutor has not shown any. Not guilty, but please buy an ice drill."

Step 5 · Work the real question

Open PrepTest 134, Section 3, Question 2 in your official copy from LSAC (for example in LawHub) and read it there.

Your answer

How to apply it

Write the principle as a trigger and a result. List every piece the trigger needs. Then read the application and check each piece against the facts given. Find the piece that is missing or swapped for something weaker. The correct choice names that gap. Skip choices about details the principle never mentions, or about how other people reacted.