PrepTest 157 · Section 2 · Question 8 (Parallel Reasoning)

Step 1 · Pre-Question Guidance · read this first

Question type

Parallel Reasoning

The one idea it tests

Two requirements, one met and one failed, so the result is a no.

The basic logic

X-Ray it: X happens only if A and B. A is true, but B is false. So X does not happen. This is valid. Find the choice with the same skeleton: a 'must have both' rule, the first met, the second failed, and a 'no' conclusion.

Tiny words that decide it

“only if”
“and”
“but”
“not”

Playground logic

Lulu's X-Ray: she lets a kid into her club only if they are neat and on time. Owen is neat but always late. So no club for Owen. Two needs, one missing, the answer is no.

Step 2 · The kid story

Lulu's Very Strict Club

Lulu started a clipboard club. She wrote the rule at the top of the sign-up sheet: "You can join only if you are neat AND on time." Owen wanted in. Lulu inspected him. His shirt was tucked, his shoelaces were tied, and his pencils were lined up by size. "Neat. Check." Then she checked her notes. "But you were late to lunch, late to recess, and late to my last meeting." Owen protested, "I'm the neatest kid in school!" Lulu shook her head kindly. "Neat is only half. You need both. So you can't join yet." Marcus laughed, "Good thing I'm never late!" Lulu checked his messy desk. "Also no." Priya sipped her juice box and grinned.

Step 3 · Try the model question

Lulu will let a kid join her club only if the kid is neat and on time. Owen is neat, but he is never on time. So Lulu will not let Owen join.

Which argument follows the same logical shape as Lulu's?

Step 4 · The courtroom tale

The Case of the Rejected Racehorse

"Your Honor," said the owner's lawyer, "my client's horse was unfairly banned from the derby!" Mr. Whitfield stood and read aloud from the rulebook. "A horse may enter only if it has a vet certificate and a registered rider." He held up a paper. "The horse has a fine certificate. I grant that." Then he held up an empty form. "But no registered rider. Not one." The lawyer sputtered, "It's the healthiest horse in the county!" Mr. Whitfield nodded. "Healthy is one half. The rule demands both halves. One missing means no entry." The judge banged her gavel. "The ban stands."

Step 5 · Work the real question

Open PrepTest 157, Section 2, Question 8 in your official copy from LSAC (for example in LawHub) and read it there.

Your answer

How to apply it

X-Ray the original: a rule with 'only if' that needs two things, then a fact that the first is met, a fact that the second fails, and a 'no' conclusion. Write it as letters. Check each choice's skeleton, not its topic. Watch for rules phrased with 'if' instead of 'only if', conclusions that say yes instead of no, both conditions met, or a hedged conclusion. Pick the exact match.