LR Masters

This class is recommended for those with 80 and above on their LR dashboard.

Logical Reasoning

Test 151, Section 2, Q18 — Namib Desert

Test 151, Section 3, Q19 — Economist

Test 150, Section 2, Q21 — Chimp feelings

Highlights

Think of necessary assumptions as required ingredients—without them, the recipe (or argument) is incomplete. If an argument lacks a necessary assumption, the conclusion can’t be proven. Many students often overlook that sometimes the necessary assumption is the only missing ingredient. When it’s added, the argument becomes complete, and the conclusion is proven. In these cases, the necessary assumption also happens to be sufficient. A helpful way to spot necessary assumptions is recognizing when an argument is incomplete and asking: What else must be true to prove the conclusion?