Logical Reasoning · Inference

PrepTest 151 · Section 2 · Question 22

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

Step 1 · Pre-Question Guidance · read this first

Question type

Inference

The one idea it tests

Chain the conditionals, then the 'must be false' answer is the one that claims a case where the chain starts but does not finish.

The basic logic

Turn each statement into an arrow. Flip any 'no X can be Y' into its contrapositive so the arrows link. Build the long chain. A 'must be false' answer says some thing has the first link of the chain but not the last. Watch out for a statement that only says something 'may' happen: it builds no arrow.

Tiny words that decide it

“must”
“no”
“any”
“may”

Playground logic

Front table means did not forget homework, which means line leader, which means reading log done. So 'some kid at the front table has no reading log done' breaks the chain. The recess line is a 'may' fact: it adds nothing to the chain.

Step 2 · The kid story

Ms. Rivera's Class Rules

Ms. Rivera posts four rules. One: to be line leader, you must have finished your reading log. Two: even kids who forgot homework may still go to recess. Three: no kid who forgot homework can sit at the front table. Four: any kid who did not forget homework gets to be line leader. Lulu draws arrows on her clipboard. "Front table means you did not forget homework. Did not forget means line leader. Line leader means reading log done." Marcus scratches his head. "And recess?" "Recess is just a 'may,'" says Lulu. "It does not connect to anything." Priya smiles. "So if someone at the front table has an unfinished reading log, the rules are broken. That cannot happen."

Step 3 · Try the model question

To be line leader, a kid must have finished the reading log. Kids who forgot homework may still go to recess. No kid who forgot homework can sit at the front table. Any kid who did not forget homework gets to be line leader.

If all of the class rules hold, which choice cannot be true?

Step 4 · The courtroom tale

The Trial of the Missing Bandstand Pass

At a county fair hearing, the rules are read aloud. To ride the big wheel, you must have a wristband. Anyone without a ticket can still visit the petting barn. No one without a ticket may enter the bandstand. Anyone with a ticket may ride the big wheel. A witness claims, "I saw a man in the bandstand with no wristband." Mr. Whitfield smiles. "Your Honor, follow the arrows. Bandstand means ticket. Ticket means big wheel rider. Rider means wristband. A bandstand guest with no wristband cannot exist under these rules." The judge nods. "And the petting barn?" "A dead end, Your Honor. It links to nothing."

Step 5 · Work the real question

Open PrepTest 151, Section 2, Question 22 in your official copy from LSAC (for example in LawHub) and read it there.

Your answer

How to apply it

Write each statement as an arrow. Turn 'no A can be B' into 'B leads to not A' so the pieces join. Set aside any statement that only says something can or may happen. Build the full chain from start to end. Then test each choice: the one that must be false claims a case that starts the chain and skips its end. Choices that run arrows backward or rely on the 'may' statement can still be true.