Logical Reasoning · Most Strongly Supported

PrepTest 151 · Section 3 · Question 1

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

Step 1 · Pre-Question Guidance · read this first

Question type

Most Strongly Supported

The one idea it tests

Take away one part, and a reaction disappears. That points to the job of that part.

The basic logic

Read the facts like a lab notebook: a reaction happens, then a part gets blocked, then the reaction stops. Pick the answer that the facts point to without stretching. Stay inside the lunchbox.

Tiny words that decide it

“no longer”
“otherwise”
“most strongly”

Playground logic

Lulu's robot stops when she claps. Then she tapes over one tiny hole, and the clap does nothing. The patty is the before-and-after test, and the safe bite from the lunchbox is: that hole helps the robot notice claps.

Step 2 · The kid story

The Robot That Stopped Listening

Lulu got a toy robot for her birthday. It rolls across the kitchen floor. When Lulu claps, it stops and blinks. When nobody claps, it just keeps rolling. Lulu wrote it all down on her clipboard. Then she found a tiny hole on the robot's back. She put a piece of tape over the hole. She clapped. The robot kept rolling, blinking at nothing. She clapped louder. Still rolling. Marcus said, "Your robot is broken forever." Lulu peeled off the tape and clapped. The robot stopped right away. "Not broken," Lulu said. "I think that little hole is how it hears me." Priya sipped her juice box. "That is the safest thing your notes can say," she nodded.

Step 3 · Try the model question

Whenever Lulu claps, her toy robot stops rolling; with no clap, it keeps rolling. After Lulu covers a tiny hole on its back with tape, clapping no longer makes it stop.

Which one of the following is best backed up by Lulu's observations?

Step 4 · The courtroom tale

The Case of the Silent Doorbell

Judge Patel looked at the doorbell. Mr. Whitfield snapped his suspenders. "Your Honor, this doorbell chimes whenever someone presses it. My client's neighbor stuck a sticker over the little sensor window. After that, pressing did nothing. Peel the sticker, and it chimes again." The other lawyer jumped up. "So the doorbell hates stickers!" Mr. Whitfield smiled. "No. The facts only show that the little window is part of how it notices a press. Nothing more, nothing less." The judge nodded. "Before, after, and one change. I will take the modest reading."

Step 5 · Work the real question

Open PrepTest 151, Section 3, Question 1 in your official copy from LSAC (for example in LawHub) and read it there.

Your answer

How to apply it

First, list the facts in order: what happens normally, what changes, and what stops happening. Notice the single thing that was changed. Then ask what those facts quietly point to, without adding feelings, the wild, training, or any big claims. Use the Lunchbox Rule: every word of the right answer should be backed by the notes. Cross out anything stronger or anything about a different situation. The keyed answer is B.