VIPLSATCracking LSAT makes you a VIP.

Logical Reasoning · Parallel Reasoning

PrepTest 129 · Section 2 · Question 19

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

Step 1 · Pre-Question Guidance · read this first

Question type
Parallel Reasoning
The one idea it tests
Match a chain of 'requires' links that ends with: no last link, no first result.
The basic logic
X-Ray the skeleton: A requires B, B requires C, so without C you will not get A. Find the choice with the same chain, in the same direction, ending in the same contrapositive move. Topic does not matter at all.
Tiny words that decide it
  • “requires”
  • “only if”
  • “unless”
  • “not”

Playground logic

Tommy's X-Ray: dessert requires a clean plate, and a clean plate requires sitting at the table. So no sitting, no dessert. The burger is just a chain of needs, and the top bun follows the chain backward from the last missing link.

Step 2 · The kid story

Tommy's Dessert Chain

Tommy wanted dessert. Badly. Lulu checked her clipboard. 'House rules,' she read. 'Getting dessert requires a clean dinner plate. A clean dinner plate requires sitting at the table, because Mom won't count food you carried to the couch.' Tommy flopped onto the couch with his plate. 'Then I guess I'm doomed,' he said. 'Correct,' said Lulu. 'If you don't sit at the table, you won't get dessert.' Marcus tried to help. 'So if you DO sit at the table, you get dessert for sure!' Priya laughed. 'Nope. Sitting is needed, not enough. You still have to finish the broccoli.' Tommy slowly carried his plate back to the table. Mr. Whiskers took his spot on the couch.

Step 3 · Try the model question

Getting dessert requires a clean plate. A clean plate requires sitting at the table. So you will not get dessert if you do not sit at the table.

Which choice follows the same reasoning skeleton as the argument above?

Choices

Step 4 · The courtroom tale

The Kite Festival Permit

Judge Okafor tapped the rulebook. 'The kite festival requires a park permit. A park permit requires proof of insurance.' Mr. Whitfield frowned at his client, a cheerful kite maker. 'Did you buy insurance?' 'Well, no,' she said. 'Then, Your Honor,' Mr. Whitfield sighed, 'I must admit the chain is clear. No insurance means no permit, and no permit means no festival.' The kite maker gasped. 'But if I buy insurance, I get the festival, right?' Judge Okafor smiled. 'Insurance is one link you need. It is not a golden ticket. You still need the permit itself.' The jury nodded. A chain of needs only runs one way.

Step 5 · Work the real question

Open PrepTest 129, Section 2, Question 19 in your official copy from LSAC (for example in LawHub) and read it there.

Your answer

How to apply it

Strip the argument down to letters: what needs what, and what the conclusion says happens when a link is missing. Write the skeleton, such as A needs B, B needs C, so no C means no A. Test each choice by writing its skeleton too. Throw out any choice where a link points the wrong way, where a need becomes a guarantee, or where the ending skips a link. Ignore the topic completely.