Logical Reasoning · Necessary Assumption

PrepTest 137 · Section 2 · Question 6

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

Step 1 · Pre-Question Guidance · read this first

Question type

Necessary Assumption

The one idea it tests

When a premise names a harmful category and the conclusion blames a policy, the argument needs the policy's effect to fall in that category.

The basic logic

Premise: anything of type X causes harm. Evidence: the policy creates effect Y. Conclusion: the policy is unwise. The gap is that Y must be a type X thing. Pull the Plank: if Y does not cause X, the argument falls.

Tiny words that decide it

“anything”
“so”
“because”

Playground logic

Kevin's patty says anything that hurts team spirit costs games, and letting the captain pick snacks first opens a big gap between the captain and everyone else. His top bun says that is a bad idea. The secret sauce: a big gap like that hurts team spirit.

Step 2 · The kid story

Kevin's Snack Rule

The kickball team is meeting under the slide. Kevin, still holding a toy stegosaurus, has a speech. 'Coach says anything that hurts team spirit makes us lose games. And now she wants the captain to pick snacks first every day! That means Marcus gets the pineapple pizza bites and the rest of us get raisins. That's a huge difference!' 'So?' says Marcus, chewing. 'So it's a bad idea!' Priya raises her juice box. 'Wait. Your argument only works if a big snack gap actually hurts team spirit. If nobody cares about snacks, your rule doesn't matter.' Kevin pauses. Nadia and Owen look at the raisins, then at Marcus. They care. The plank holds.

Step 3 · Try the model question

Kevin: Anything that hurts team spirit makes our kickball team lose more games. That is why letting the captain pick snacks first is a bad idea: it creates a large gap between what the captain gets and what everyone else gets.

Kevin's argument requires assuming which one of the following?

Step 4 · The courtroom tale

The Window Seat Policy

A school bus company was sued for giving window seats to the bus monitors every day. The parents' lawyer said: 'Anything that makes the ride stressful makes kids late to class. This policy creates a big gap between monitors and riders. So it must go.' Mr. Whitfield rose. 'Your Honor, does this seat gap actually make the ride stressful?' The lawyer blinked. 'It must, or my argument has no bridge.' The judge nodded. 'Then that is what you are assuming. Prove it, and you win.'

Step 5 · Work the real question

Open PrepTest 137, Section 2, Question 6 in your official copy from LSAC (for example in LawHub) and read it there.

Your answer

How to apply it

Find the general rule in the premises (anything of a kind causes harm) and the specific effect the policy produces. Ask: what must link that effect to the harmful kind? Predict it. Then use Pull the Plank on each choice: negate it and see if the argument breaks. Reject choices that are stronger than needed, talk about overall results, or bring in new comparisons.