PrepTest 146 · Section 3 · Question 13 (Parallel Reasoning)

Step 1 · Pre-Question Guidance · read this first

Question type

Parallel Reasoning

The one idea it tests

A clean chain: if every A is B and every B is C, then every A is C.

The basic logic

X-ray the stimulus into letters. Check the direction of each arrow and that the middle term links them. Then find the choice with the same valid chain, not just the same words.

Tiny words that decide it

“wherever”
“all”
“so”

Playground logic

Priya's X-ray: every chess club kid stays after school, and everyone who stays after school rides the late bus, so every chess club kid rides the late bus. A to B, B to C, so A to C. The match must chain the arrows the same way, with the middle piece doing the linking.

Step 2 · The kid story

Priya's Arrow Chain

Nadia asked Priya how she always knows who's on the late bus. Priya pulled out a napkin. 'Every kid in chess club stays after school. Everyone who stays after school rides the late bus. So every chess club kid rides the late bus.' She drew: chess, arrow, after school, arrow, late bus. 'See? The arrows connect like train cars.' Marcus barged in. 'Easy. Everyone on the late bus is in chess club!' Priya shook her head. 'You drove the train backward. Lots of kids stay late for art or soccer.' Kevin tried. 'Some chess kids like pineapple pizza, and pizza kids ride the bus, so...' 'Some isn't all, Kevin. Your train fell apart.' Nadia grinned. 'So I need every car hooked in the same direction.' Priya sipped her juice box. 'Choo choo.'

Step 3 · Try the model question

Every kid in chess club stays after school, and every kid who stays after school rides the late bus. So every kid in chess club rides the late bus.

Which one of these arguments has reasoning most like the reasoning above?

Step 4 · The courtroom tale

The Case of the Muddy Boots

A farmer was accused of tracking mud into the town hall. The prosecutor reasoned, 'Your Honor, everyone who works the north field walks the creek path. Everyone who walks the creek path gets muddy boots. The farmer works the north field. So the farmer had muddy boots.' The judge nodded. 'Field to path, path to mud. That chain holds.' Mr. Whitfield stood. 'Agreed, Your Honor. But the prosecutor's helper argued earlier that anyone with muddy boots works the north field. That chain runs backward.' The judge sighed. 'Then I keep the first argument and toss the second. Same pieces, opposite arrows, very different logic.'

Step 5 · Work the real question

Open PrepTest 146, Section 3, Question 13 in your official copy from LSAC (for example in LawHub) and read it there.

Your answer

How to apply it

Turn the stimulus into letters: every A is B, every B is C, so every A is C. For each choice, write its letters too. Check three things: are the quantity words the same (all, not some or many), does each arrow point the same way, and does the conclusion connect the first term to the last. Reject any choice whose arrows are reversed or whose middle term fails to link.