Logical Reasoning · Inference

PrepTest 124 · Section 2 · Question 25

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

Step 1 · Pre-Question Guidance · read this first

Question type

Inference (Must Be True)

The one idea it tests

Two most statements about the same group must overlap, and then an all statement carries that overlap forward.

The basic logic

If most of group S have trait H and most of S have trait G, at least one member of S has both. Then if every G has trait O, that member has O too. So some H have O. Use the Lunchbox Rule: claim nothing stronger than some.

Tiny words that decide it

“most”
“all”
“some”

Playground logic

Most art club kids love glitter, and most art club kids ride the bus, so at least one glitter lover rides the bus. All bus riders wake up early, so some glitter lovers wake up early. That is all the lunchbox holds.

Step 2 · The kid story

Lulu's Art Club Survey

Lulu surveyed the art club with her clipboard. "Most art club kids love glitter. Most art club kids ride the bus. And every bus rider wakes up before 6:30." Marcus jumped in. "So most early risers love glitter!" Priya shook her head and sipped her juice box. "Too strong. But here's what's safe. If more than half love glitter and more than half ride the bus, those halves have to overlap. At least one kid is in both." Lulu nodded slowly. "And that kid rides the bus, so that kid wakes up early." "So some glitter lovers wake up early," Priya said. "That's all. Not most. Not all." Kevin raised his hand. "Does a glitter dinosaur count?" Lulu wrote: no.

Step 3 · Try the model question

Most kids in the art club love glitter, and most kids in the art club ride the bus. Also, every kid who rides the bus wakes up before 6:30.

If these statements are true, which of the following must also be true?

Step 4 · The courtroom tale

The Case of the Marching Band Shoes

A shoe store claimed in a fictional lawsuit that it deserved credit for the band's success. Mr. Whitfield laid out the facts. "Your Honor, most band members bought shoes at the store. Most band members also play brass. And every brass player practices on Saturdays." Judge Kim tapped her pen. "So what follows?" "At least one shopper plays brass, Your Honor, since two majorities of one band must share somebody. So at least one shopper practices Saturdays." The store's lawyer jumped up. "So most Saturday practicers shop with us!" The judge shook her head. "Counsel, the facts give you some. Not most. Sit down."

Step 5 · Work the real question

Open PrepTest 124, Section 2, Question 25 in your official copy from LSAC (for example in LawHub) and read it there.

Your answer

How to apply it

Translate each statement into most, all, or some, and note which group they share. If two mosts describe the same group, mark a guaranteed overlap. Then follow any all statement forward from that overlap. The right answer will be a modest some claim that chains those pieces. Eliminate choices using most or all, choices that reverse an all statement, and choices about members not covered.