Logical Reasoning · Principle

PrepTest 101 · Section 2 · Question 9

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

Step 1 · Pre-Question Guidance · read this first

Question type

Principle (justify)

The one idea it tests

Find the rule that turns the facts in the premises into the label in the conclusion.

The basic logic

List what the premises say happened. Then find the new label the conclusion pins on some people. The principle you want is a bridge: 'doing that kind of thing counts as earning that label.' Rules about other labels or other actions do not build the bridge.

Tiny words that decide it

“whoever”
“at least some”
“later”
“so”

Playground logic

Owen's crew of regular kids knocked down castles for a moat that later proved impossible. Lulu concludes some regular kids were wreckers. The missing secret sauce is a rule saying that knocking things down for a plan later found impossible counts as wrecking.

Step 2 · The kid story

The Great Moat Disaster

Owen's crew at the beach was mostly regular kids, not the bossy ones. They wanted to build the Grand Moat, the best moat ever, all the way around the lifeguard stand. To make room, they knocked down six sandcastles other kids had built. Then they discovered the sand was too dry: the moat could never hold water. It was impossible all along. Nadia, whose castle got flattened, was furious. 'Only Marcus is a wrecker, he was the bossy one,' said Owen. Lulu wrote it all down. 'You were mostly regular kids. You knocked down castles for a plan that turned out to be impossible. If knocking down castles for an impossible plan counts as wrecking, then some regular kids here were wreckers too.' Owen looked at his shovel and went quiet.

Step 3 · Try the model question

Lulu argues: Anyone who thinks only Marcus wrecked castles is missing something. Owen's crew was mostly regular kids, and the crew knocked down castles to build a moat that later proved impossible. So some regular kids were wreckers.

Which principle, if valid, best justifies Lulu's reasoning?

Step 4 · The courtroom tale

The Canal That Could Not Flow

A town council, made up of everyday shopkeepers, tore down a row of old barns to dig a canal meant to bring ships right to Main Street. Engineers later proved no ship could ever reach the town that way. At the hearing, the council's lawyer said, 'Only the chairman was reckless. The others were ordinary folks.' Mr. Whitfield rose. 'Your Honor, ordinary folks voted to tear down those barns for a goal later shown impossible. If destroying property for an impossible goal counts as wrongful destruction, then the ordinary members share the blame.' The judge said, 'So your case needs that rule to hold.' 'Yes, Your Honor. Grant the rule, and the conclusion follows.'

Step 5 · Work the real question

Open PrepTest 101, Section 2, Question 9 in your official copy from LSAC (for example in LawHub) and read it there.

Your answer

How to apply it

Start with the top bun and circle the label it pins on some people. Then list what the premises say those people did, and what was later learned about their goal. Pre-phrase the bridge: 'doing that, for that kind of goal, counts as earning that label.' Pick the principle that builds that exact bridge. Eliminate rules that judge the act without supplying the label (Whispers), rules about a different label the argument is pushing against (Matching Costumes), and rules that would support the view being rejected (Saboteurs).