Logical Reasoning · Inference (Complete the Argument)

PrepTest 137 · Section 2 · Question 5

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

Step 1 · Pre-Question Guidance · read this first

Question type

Inference / Must Be True (complete the argument)

The one idea it tests

If one thing guards against two causes of a problem, losing that guard probably raises the risk of the problem.

The basic logic

Link the chain: a protector reduces two things; each of those things pushes toward a bad outcome. The blank should say that less of the protector means more risk of the outcome. Watch the strength: the evidence supports 'increased risk', not 'certain' or 'only'.

Tiny words that decide it

“probably”
“so”
“risk”

Playground logic

Owen's chain cover blocks rust and blocks mud, and both rust and mud make breakdowns more likely. The Lunchbox Rule says the fair ending is modest: losing the cover raises the risk of a breakdown, nothing stronger.

Step 2 · The kid story

Owen's Naked Chain

Owen's bike has a plastic chain cover. Grandpa explains what it does while fixing a flat. 'That cover keeps rain off the chain, so it doesn't rust. It also keeps mud from caking on it.' He wipes his hands. 'Rust makes a chain snap. And a muddy chain probably slips off more often.' Owen thinks hard. 'So if I take the cover off because it looks babyish...' 'Then?' asks Grandpa. Marcus jumps in. 'Then your bike will definitely explode!' Lulu corrects him gently: 'No. Then there's good reason to expect his bike is more likely to break down. That's all the clues tell us.' Owen leaves the cover on. Biscuit sniffs the chain and sneezes.

Step 3 · Try the model question

A bike's chain cover keeps rain from rusting the chain and keeps mud off it. Rust causes chains to snap, and chains caked in mud probably slip off more often. So we have good grounds to expect that ____.

Which choice best fills in the blank?

Step 4 · The courtroom tale

The Missing Beach Flag

A town removed the tall flag on its beach tower. A swimmer's group sued. Their lawyer, Ms. Duarte, argued: 'Your Honor, that flag warned swimmers about rip currents and about jellyfish days. Rip currents cause rescues, and jellyfish days probably cause more panicked swimmers. So we have grounds to expect that removing the flag raises the risk of beach rescues.' Mr. Whitfield objected: 'She can't prove every swimmer will need rescue!' The judge replied, 'She didn't claim that. She claimed more risk, and the evidence supports exactly that much.'

Step 5 · Work the real question

Open PrepTest 137, Section 2, Question 5 in your official copy from LSAC (for example in LawHub) and read it there.

Your answer

How to apply it

Write the chain on scratch paper: protector reduces factor one and factor two; each factor pushes toward the outcome. Predict a modest ending: less protector, more risk. Then match. Cut any choice that is stronger than the clues, runs the cause the wrong way, or brings in a claim the chain never builds. Keep the strength matched to the cautious wording.