Logical Reasoning · Strengthen

PrepTest 135 · Section 1 · Question 13

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

Step 1 · Pre-Question Guidance · read this first

Question type

Strengthen

The one idea it tests

A plan saves money on one cost, so it pays off overall only if that cost is a big slice of the whole bill.

The basic logic

Patty: one input is much cheaper with the new plan. Top bun: the plan is worth it overall, even with a smaller output. Secret sauce: that cheaper input is a large share of total costs. Strengthen by making the saved cost loom large.

Tiny words that decide it

“thus”
“although”
“much cheaper”

Playground logic

Owen's homemade paint needs more coats and covers fewer fences a day, but it is far cheaper per can. He concludes the business still saves money. That only works if paint is the big cost; prove that, and the burger stands tall.

Step 2 · The kid story

Owen's Fence Business

Owen started a summer business painting neighbors' fences. Store paint is expensive, so Aunt Rosa showed him how to mix homemade paint from chalk and glue. "It takes more coats," she warned. "You'll finish fewer fences each day." Owen did the math. Homemade paint costs about a tenth as much per bucket. "Even painting slower, I'll make more money!" Marcus folded his arms. "Says who? What if your brushes and ladders cost a fortune?" Priya pulled out a receipt. "Owen's biggest cost by far is paint. His brushes were a dollar each and the ladder is borrowed from Grandpa." Owen grinned. If paint is the big cost, cutting it cuts the whole bill. Biscuit got a stripe of white on his tail. No charge.

Step 3 · Try the model question

Homemade paint needs more coats than store paint, but each bucket costs far less. So Owen's fence-painting business should make more money using homemade paint, even though he will finish fewer fences per day.

Which choice, if true, gives the most support to Owen's reasoning?

Step 4 · The courtroom tale

The Bakery Oven Dispute

A baker named Mr. Kowalski switched to a wood-fired oven. Wood costs a fraction of what gas costs, but the oven bakes fewer loaves per hour. His business partner sued, saying the switch would sink the bakery. Mr. Whitfield snapped his suspenders and handed the judge a ledger. "Your Honor, look at the bakery's bills. Fuel was nearly half of every dollar spent. Flour and rent were small next to it." The judge studied the pages. "So a big cut in the biggest cost can outweigh baking a bit slower." "Exactly," said Mr. Whitfield. "If fuel were a tiny cost, the partner might have a point. It is not." The judge ruled for the baker.

Step 5 · Work the real question

Open PrepTest 135, Section 1, Question 13 in your official copy from LSAC (for example in LawHub) and read it there.

Your answer

How to apply it

Find the cheaper input the argument relies on, and notice the admitted drawback (less output, more of the input needed). The conclusion says the plan still pays off overall. Ask what would make the savings big enough to beat the drawback. Pick the choice that shows the saved cost is a large part of the total. Avoid choices that bring in new costs, side features, or details that do not touch cost at all.