Logical Reasoning · Inference (Complete the Argument)

PrepTest 157 · Section 2 · Question 3

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

Step 1 · Pre-Question Guidance · read this first

Question type

Inference (Complete the Argument)

The one idea it tests

A jump up followed by a slow slide down from that high point means the benefit shrinks over time, nothing more.

The basic logic

First use gives a boost over the starting level. Long-term use slowly drags results down from the boosted level. The blank must say only what follows: the payoff fades. It does not say results fall below the start, or anything about costs or other harms.

Tiny words that decide it

“initially”
“gradually”
“long-term”
“from”

Playground logic

Tommy's patty: the sticker chart gives a big jump the first week, then using it week after week slowly drags his homework count down from that high spot. The top bun can only say the chart's boost shrinks over time; the Lunchbox Rule bans anything about money, feelings, or doing worse than before.

Step 2 · The kid story

Tommy's Fading Sticker Chart

Tommy started a sticker chart for homework. Week one was amazing: he finished every assignment, way more than his usual half. Lulu wrote it all down on her clipboard. Then the weeks rolled on. Week two, a little less. Week three, a little less again. Week six, he was still above his old half, but nowhere near that first perfect week. Marcus declared, "Sticker charts are a total scam! They make kids lazier than ever!" Lulu shook her head. "Look at the numbers. He's still doing more than before the chart. The jump just keeps getting smaller." Priya sipped her juice box. "So the honest thing to say is this: the chart helps, but its help shrinks the longer he uses it." Tommy hid a sticker in his pocket for later.

Step 3 · Try the model question

The first week Tommy used a sticker chart, his finished homework jumped well above his usual level. Lulu's records show that using the chart week after week slowly lowers his finished homework from that high first week. We should conclude that Tommy's sticker chart _______.

Which choice best fills in the blank?

Step 4 · The courtroom tale

The Case of the Tired Trampoline

A trampoline park sued a spring maker. "Your Honor," said their lawyer, "the new springs made kids bounce far higher on day one. Over months, the bounce slowly sank from that height. The springs are defective and ruined our business!" Mr. Whitfield hooked his thumbs in his suspenders. "Let's read your own chart. Day one: huge bounce. Month six: still higher than your old springs, just lower than day one." He paused. "Your evidence proves one thing only: the extra bounce fades over time. It doesn't prove ruin, and it doesn't prove defect." The judge nodded. "The court finds a shrinking benefit, nothing more."

Step 5 · Work the real question

Open PrepTest 157, Section 2, Question 3 in your official copy from LSAC (for example in LawHub) and read it there.

Your answer

How to apply it

Mark the starting level, the first jump, and the slow decline, and note what the decline is measured from (the boosted level, not the start). Predict a blank that says only that the gain shrinks over time. Use the Lunchbox Rule: cross out choices bringing in costs, side harms, misuse, or a collapse below the starting point. The winner restates the fading payoff in fresh words.