Logical Reasoning · Flaw
PrepTest 115 · Section 2 · Question 2
Phase 1 (your first ~400 questions): read the guidance, then answer. No clock.
Step 1 · Pre-Question Guidance · read this first
- “some”
- “any”
- “whatever”
Playground logic
Marcus has a rule that games teaching teamwork help you later, and some board games teach teamwork. Then his top bun says every board game helps every kid. The patty only covers some games, but the conclusion covers all of them.
Step 2 · The kid story
Marcus and the Board Game Shelf
Marcus stood in front of the classroom game shelf like a detective about to crack a case. "Fact one: any game that teaches you teamwork will help you when you grow up. Fact two: some board games teach teamwork. Case closed! Every kid in this school, no matter what, will be helped later by playing any board game on this shelf." Owen held up a box. "This one is just rolling a die and moving. Nobody works together." Priya nodded and sipped her juice box. "Your clue only shows that some games teach teamwork, Marcus. You concluded something about all of them." Marcus squinted at the box. "Maybe it teaches teamwork with the die?" Nadia laughed. "The die is not on your team, Marcus."
Step 3 · Try the model question
Marcus: Any game that teaches teamwork will help kids when they grow up. Some board games teach teamwork. So every kid will be helped later in life by playing any board game.
Marcus's reasoning is flawed because it
Step 4 · The courtroom tale
The Cookbook Promise
A publisher was sued over an ad for its cookbook. The ad said: any recipe that uses fresh herbs tastes amazing, and some recipes in this book use fresh herbs, so every recipe in this book will taste amazing to every cook. A customer stood up holding a plate of gray noodles. "Your Honor, this recipe has no herbs at all." Mr. Whitfield, for the customer, snapped his suspenders. "The ad's facts are about some recipes. Its promise is about all of them. You cannot sell 'every' when you only proved 'some.'" The judge tasted a noodle, made a face, and ruled for the customer. "Some is not all," she said, reaching for a glass of water.
Step 5 · Work the real question
Open PrepTest 115, Section 2, Question 2 in your official copy from LSAC (for example in LawHub) and read it there.
Your answer
How to apply it
Lay out the burger: one premise is a general rule, the other is a fact about part of a group. Circle the quantity words in each premise and in the conclusion. If the evidence says 'some' and the conclusion says 'any' or 'every,' you have found the Scope Shift. Pick the choice that describes reaching a claim about a whole category from support that only covers part of it. Reject choices naming flaws whose pieces never appear in the argument.