Logical Reasoning · Flaw

PrepTest 115 · Section 4 · Question 21

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

Step 1 · Pre-Question Guidance · read this first

Question type

Flaw

The one idea it tests

'All the complaints were about X' means little if X is the only one around.

The basic logic

The argument notices that every complaint in some group targets one person and calls that person bad. Ask: how many others were there to complain about? If the target is the only one doing the job, of course every complaint lands there.

Tiny words that decide it

“every”
“so”
“good evidence”

Playground logic

Marcus's top bun: Kevin is a terrible cookie baker. His patty: every cookie complaint at the bake sale was about Kevin's cookies. The missing check: were there any other cookie bakers at all? If Kevin was the only one, every complaint had nowhere else to go.

Step 2 · The kid story

Kevin's Cookie Complaints

After the school bake sale, Marcus waved the complaint jar. "Six complaints about cookies, and every one is about Kevin's cookies. Case closed. Kevin is a bad baker." Kevin looked sad and ate a dinosaur-shaped cookie to feel better. Lulu flipped through her clipboard. "Marcus, who else brought cookies?" Marcus opened his mouth, then shut it. Priya checked the sign-up sheet. "Nobody. Kevin baked every cookie at the sale. Two hundred of them." Nadia laughed. "So of course every cookie complaint is about Kevin. There was no one else to complain about." "And six complaints out of two hundred cookies," Owen added, "is not that many." Kevin brightened. "Also one complaint just says the dinosaurs were too cute to eat." Marcus put down the jar. "I may need more clues."

Step 3 · Try the model question

Marcus: Every complaint about cookies at the bake sale was about Kevin's cookies. So we have strong proof that Kevin is a poor baker whose cookies cannot be trusted.

Marcus's argument is weak because it ignores the chance that

Step 4 · The courtroom tale

The Only Ice Cream Truck

A town council lawyer stood before Judge Reyes. "Every complaint about ice cream trucks this summer named Ms. Bloom's truck. Clearly her ice cream is dreadful." Mr. Whitfield rose slowly, adjusting his suspenders. "Your Honor, how many ice cream trucks drive in this town?" The lawyer checked her notes. "One." "One," repeated Mr. Whitfield. "Then every single complaint had to be about her truck. A town with one truck cannot spread its grumbles around." The judge set down her pen. "Without other trucks to compare, these complaints tell us almost nothing."

Step 5 · Work the real question

Open PrepTest 115, Section 4, Question 21 in your official copy from LSAC (for example in LawHub) and read it there.

Your answer

How to apply it

Spot the 'every complaint was about this one' evidence and the 'so this one is bad' conclusion. Ask how many others were in the comparison pool. Look for the choice that raises the chance there was little or no competition to complain about. Skip choices about people outside the group, about different kinds of complaints, or about the target's size, unless they connect to that missing comparison.