Logical Reasoning · Sufficient Assumption

PrepTest 130 · Section 3 · Question 13

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

Step 1 · Pre-Question Guidance · read this first

Question type

Sufficient Assumption

The one idea it tests

Connect the premise's key idea directly to the conclusion's new idea with a rule.

The basic logic

Premise: the practice does A, and thereby B. Conclusion: the practice does C. A magic key rule, 'anything that does A does C', clicks the conclusion into place. The 'thereby' step can be a distraction.

Tiny words that decide it

“thereby”
“hence”
“if... then”

Playground logic

Lulu's patty: Kevin's reused drawing makes all his assignments look alike, and thereby hides what each one asked. Her top bun: it misleads Ms. Rivera into thinking he learned nothing new. The magic key: anything that makes assignments look alike misleads the teacher that way.

Step 2 · The kid story

Kevin's Forever Dinosaur

Kevin has one favorite drawing: a T. rex eating pineapple pizza. He staples it to every assignment: the fractions sheet, the weather report, even the poem about autumn leaves. Lulu, visiting from second grade, studied the pile. "Kevin, your dinosaur makes every assignment look the same. That hides what each one was really about. So Ms. Rivera will think you learned nothing new all month." Priya raised a finger. "Lulu, your jump needs a rule: anything that makes assignments look the same tricks a teacher into thinking nothing new was learned. Add that rule, and click, your conclusion locks in." Lulu wrote the rule on her clipboard. Kevin hugged his T. rex. "He is still a very good dinosaur."

Step 3 · Try the model question

Kevin staples the same dinosaur drawing to every assignment. This makes all his assignments look alike, and so it hides what each assignment asked. Therefore, Kevin's habit misleads Ms. Rivera into thinking he learned nothing new.

Lulu's conclusion follows logically once we assume which statement?

Step 4 · The courtroom tale

The Case of the One Cake Photo

At the Bakery Court, a lawyer named Ms. Frost argued against a cake shop. "Your Honor, this shop uses the same cake photo on every menu card. That makes all its cakes look alike, and thereby hides each cake's flavor. Hence the shop misleads customers into thinking every cake tastes the same." Mr. Whitfield, for once, agreed with the logic but not the gap. "Your Honor, Ms. Frost needs a rule: whatever makes cakes look alike misleads customers into thinking they taste alike. Without it, her last step floats." The judge nodded. "Ms. Frost, add that rule and your conclusion follows. Can you support it?" Ms. Frost reached for a thick folder.

Step 5 · Work the real question

Open PrepTest 130, Section 3, Question 13 in your official copy from LSAC (for example in LawHub) and read it there.

Your answer

How to apply it

Map the burger: the premises give a first claim and a 'thereby' claim, and the conclusion brings its own new idea. Find the idea that shows up in the conclusion but nowhere in the premises as a result. Build a rule that starts from a premise idea and ends at that new conclusion idea. Run the Click Test on each choice: add it and see whether the conclusion locks in. Reversed rules and rules ending somewhere else fail.