Day 57 / 168 Week 10 of 28 Phase 2: Logical Reasoning Deep Dive

Parallel Reasoning II: Formal / Conditional Parallel

🕑 ~80 min · Archetype A — LR Deep Dive

Parallel Reasoning II: Formal / Conditional Parallel

When the stimulus is built from conditionals, Parallel Reasoning becomes almost purely mechanical: diagram the stimulus's logical form, then diagram each answer choice and match.

1. Diagram Both Sides

Reduce the stimulus to its bare logical form (e.g., "p→q, ¬q, therefore ¬p" — a valid modus tollens). Then check each choice's form against it directly.

2. Valid Matches Valid; Invalid Matches Invalid

A choice with the identical logical form but drawing the opposite (invalid) conclusion is not a match, even if the topic and premises feel similar.

Practice items on this page are curriculum-authored in LSAT style; they are not official LSAC questions. Real drilling happens on LawHub — see the assignment below.

Q1. Stimulus: "If the store is open, the lights are on. The lights are off. So the store is not open." (Valid modus tollens.) Which choice matches?

A. If it rains, the field floods. The field flooded, so it rained.

B. If the alarm is armed, the light blinks. The light isn't blinking, so the alarm isn't armed.

C. If she studies, she passes. She passed, so she studied.

D. If the machine is on, it hums. The machine is on.

Correct answer: B. Same valid modus tollens form: p→q, ¬q, therefore ¬p. The other choices commit reversal errors or are incomplete.

LawHub drill-tier LR section, untimed. Scan for conditional-heavy Parallel stimuli.

An RC maintenance day on science passages tomorrow, then Parallel Flaw closes the pair.

← Day 56: Parallel Reasoning I: Matching Argument Structure Day 58: RC Maintenance: Science Passages →