Day 30 / 168 Week 5 of 28 Phase 2: Logical Reasoning Deep Dive

Week 5 Synthesis: Flaw vs Necessary Assumption

🕑 ~130 min · Archetype C — Synthesis / Timed

Week 5 Synthesis: Flaw vs. Necessary Assumption

These two types often examine the same underlying gap but ask for different things: Flaw describes the error in the abstract; Necessary Assumption asks you to supply the missing piece that would fix it. Today makes that contrast concrete.

Decision Matrix

	Flaw	Necessary Assumption
Task	Describe what's wrong	Identify what's required (but unstated)
Answer style	Abstract description of the error	A specific unstated claim
Verification tool	Match the description to the specific gap	The negation test
Relationship	Names the hole	Names (one thing that) would fill it

Official Timed Section

One drill-tier LR section, timed at 35 minutes, mixed question types. Blind-review and log.

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. An argument has a causal flaw (ignores an alternate cause). Which of the following would most likely be the correct Necessary Assumption answer for the same argument?

A. A description of the flaw itself

B. A claim ruling out the specific alternate cause

C. An unrelated fact about the topic

D. A restatement of the conclusion

Correct answer: B. The necessary assumption that repairs a causal flaw is typically a claim ruling out the specific alternate cause the argument overlooked.

Week 6: Sufficient Assumption, the stronger cousin of Necessary Assumption, followed by Strengthen — the first true "make it better" question type.

← Day 29: Necessary Assumption II: Defender Assumptions & "Takes for Granted" Day 31: Sufficient Assumption I: Bridging the Gap →