Logical Reasoning · Weaken

PrepTest 116 · Section 3 · Question 12

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

Step 1 · Pre-Question Guidance · read this first

Question type

Weaken

The one idea it tests

When a claim depends on a definition, evidence that fails one part of the definition stops counting as evidence.

The basic logic

Read the definition first and list its required parts. Then check whether the evidence really meets each part. The best weakener shows the example misses a required piece, so the example no longer proves the skill at all.

Tiny words that decide it

“requires”
“never”
“only if”

Playground logic

Marcus claims Owen can sight-read, which means playing music he has never seen. His patty is one great first performance. Pop! If Owen had practiced that song all summer, the example fails the 'never seen' part of the definition, and the evidence falls apart.

Step 2 · The kid story

Owen's Big Recital

Ms. Rivera explains that sight-reading means playing a piece of music you have never seen before, straight off the page. Marcus jumps up. "Owen can totally sight-read! At the spring recital, they handed him a long song and he played it perfectly. First try!" Owen turns pink. Priya sips her juice box thoughtfully. "Owen, had you ever seen that song before?" Owen scratches his head. "Well... I practiced it every week at my lessons all summer." Lulu taps her clipboard. "Then it wasn't new to you. That doesn't match the definition." Marcus deflates like a beach ball. "So the recital proves he's good at that song, not that he can sight-read?" "Exactly," says Priya. "Great playing. Wrong evidence." Owen grins anyway. He did play beautifully.

Step 3 · Try the model question

Sight-reading is playing a piece of music you have never seen before. Marcus says Owen can sight-read. As proof, he points out that at the spring recital Owen was handed a long song and played it perfectly on the first try.

Suppose each choice is true. Which one hurts Marcus's proof the most?

Step 4 · The courtroom tale

The Case of the Mystery Chef

In a fictional cooking contest appeal, the rules define improvising as cooking a dish from ingredients you've never been told in advance. A contestant claims a rival is a great improviser. "She made a perfect stew from the mystery basket!" Mr. Whitfield rises. "Your Honor, I have the basket list. It was posted on the contest website a week early. The rival practiced that stew five times." The judge raises an eyebrow. "So she met the dish, but not the definition." "Exactly. A great stew, but not improvising. The proof needed ingredients she'd never been told about." The judge sets down his pen. "The example is excused from evidence. Delicious, though, I'm sure."

Step 5 · Work the real question

Open PrepTest 116, Section 3, Question 12 in your official copy from LSAC (for example in LawHub) and read it there.

Your answer

How to apply it

Write down the definition and break it into required parts. Find the single example offered as evidence. Ask which part of the definition the example might not meet. The best answer shows the example fails one of those required parts, so it stops counting as proof. Ignore answers that only describe the example in more detail, mention other cases, or talk about how the task was done rather than whether it fits the definition.