Logical Reasoning · Inference (Complete the Argument)

PrepTest 157 · Section 2 · Question 7

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

When the 'same speed' assumption predicts far fewer survivors than we see, the assumption must be false.

The basic logic

Two versions of a thing: one moving fast, one nearly still. The still ones break down quickly, faster than the trip takes. If the fast ones broke down just as fast, almost none would arrive. Many do. So the fast ones break down more slowly. The blank finishes that if-then by rejecting its 'if'.

Tiny words that decide it

“if”
“then”
“apparently”
“typically”

Playground logic

Priya's patty: counter ice pops melt in five minutes, and the scooter ride takes thirty. If scooter pops melted as fast, nearly all would arrive as puddles, but most arrive solid. Top bun: scooter pops must melt more slowly than counter pops.

Step 2 · The kid story

The Ice Pop Mystery

Aunt Rosa delivers ice pops to the park on her zippy scooter. The ride takes thirty minutes. Tommy tested pops sitting on the kitchen counter: every one melted into a puddle in five minutes. "So Aunt Rosa's pops must arrive as soup!" Marcus declared. But Lulu had been counting at the park all week. "Ninety out of every hundred show up frozen." Marcus scratched his head. "That's impossible." Priya sipped her juice box. "Only if scooter pops melt as fast as counter pops. If they did, we'd get maybe one or two solid ones. We get ninety. So scooter pops must melt much more slowly than counter pops." Lulu wrote it down. "Maybe the cooler bag helps." Priya smiled. "Maybe. But the numbers already tell us what's happening."

Step 3 · Try the model question

Ice pops left on the counter melt in about five minutes. The scooter ride to the park takes thirty minutes. If pops on the scooter melted as fast as pops on the counter, only about one in a hundred would arrive frozen. Yet about ninety in a hundred arrive frozen. Apparently, pops on the scooter _______.

Which choice fills the blank best?

Step 4 · The courtroom tale

The Case of the Surviving Snowmen

A snowman contest was disputed. "Snowmen in sunny yards melt in an hour," argued one lawyer. "The judging takes three hours. So any snowman still standing must be fake, made of plastic!" Mr. Whitfield rose, suspenders gleaming. "Your Honor, if the shady-yard snowmen melted as fast as the sunny ones, almost none would survive judging. Yet nearly all of them survived." He tapped the table. "So shady-yard snowmen simply melt more slowly. No plastic needed." The judge examined a snowman and found it cold and wet. "Real snow. Slow melting. Case dismissed."

Step 5 · Work the real question

Open PrepTest 157, Section 2, Question 7 in your official copy from LSAC (for example in LawHub) and read it there.

Your answer

How to apply it

Separate the two versions of the thing being compared. Note how quickly the slow-moving version breaks down and how long the trip takes. Read the if-then: equal breakdown would mean only a tiny fraction arrive. Note the actual count is far higher. So the 'if' fails. Predict a blank saying the fast-moving version breaks down more slowly. Skip choices about travel time, detection, numbers produced, or origin.