Logical Reasoning · Weaken

PrepTest 108 · Section 3 · Question 2

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

A plan is praised because it removes a harm; the strongest attack shows the plan brings its own harm of the same size.

The basic logic

Spot the trade: 'our plan replaces the thing that causes damage, so it saves the victim.' The secret sauce is that the plan itself is harmless. Pop it by showing the plan causes as much damage as what it replaces.

Tiny words that decide it

“need not”
“in fact”
“since”
“threat”

Playground logic

Marcus says a giant reading fort on the classroom rug would stop kids from running there, so the fort will save the rug. The secret sauce: the fort itself is gentle on the rug. Pop it: building and using the fort wears the rug out just as fast.

Step 2 · The kid story

Marcus Saves the Rug

Ms. Rivera's classroom rug was getting threadbare because kids kept racing across it at indoor recess. Marcus had a plan. "We build a giant reading fort right in the middle. Big enough for six kids, with room for a snack corner later. Nobody can race through a fort! The fort will be the rug's hero." Priya sipped her juice box. "Hold on. The fort needs heavy wooden legs, and a cardboard wall we drag around every afternoon, and a tape path so kids line up to get in." She pointed at the rug. "Dragging a wall every day scrapes the rug too. Six kids crawling in and out all day is not exactly gentle." Marcus frowned. "So my hero might hurt the rug as much as the racing does?" "Maybe," said Priya. "Then it is not a hero. It is just a different kind of rug trouble."

Step 3 · Try the model question

Marcus: We should build a big reading fort in the middle of the classroom rug. Right now kids race across the rug at indoor recess and wear it down. Since nobody can race through a fort, the fort would protect the rug.

Suppose each choice is true. Which does the most damage to Marcus's argument?

Step 4 · The courtroom tale

The Case of the Parking Lot Garden

An invented city wanted to turn a busy parking lot into a stage for concerts. Lawyer Bianca Moss said, "Your Honor, the cars leak oil on the grass strip next door. A stage means no cars, so the grass will finally recover." Mr. Whitfield rose, thumbs in his suspenders. "Your Honor, the stage needs trucks to haul in speakers every week, a fence, and crowds of two thousand stomping across that same grass strip." Judge Lin raised an eyebrow. "So the cure may be as rough on the grass as the cars were." "Exactly," said Mr. Whitfield. "Removing one harm does not help if you bring in an equal one."

Step 5 · Work the real question

Open PrepTest 108, Section 3, Question 2 in your official copy from LSAC (for example in LawHub) and read it there.

Your answer

How to apply it

Find the conclusion: a plan will protect something because it ends a current harm. Name the secret sauce: the plan itself does not cause similar harm. Look for the choice that shows the plan brings its own damage, about as big as the one it removes. Ignore choices about who supports or opposes the plan, or how special the protected thing is. Those do not pop the argument.