Must Be True LSAT Questions With Strategy and Example

Quick answer: a Must Be True question gives you some facts and asks what they prove. There is usually no argument to judge. Accept the facts as true, combine them, and pick the only answer the text guarantees.

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How to Spot Must Be True Questions

Look for question stems like these:

If the statements above are true, which one of the following must also be true?
Which one of the following can be properly inferred from the statements above?
Which one of the following follows logically from the statements above?

How to Solve Must Be True Questions

Read the facts slowly, and note strong words like “all,” “some” and “only.”
Look for facts that connect through a shared term.
Do not predict too hard, as many things may follow.
Test each answer against the text.
Choose the one that cannot be false.

Must Be True Questions Example

This is a practice example we wrote to show the idea. It is not a real LSAT question.

Argument: All dogs at the shelter are vaccinated. Some dogs at the shelter are puppies.

Question: Which one of the following must be true?

Best answer: Some puppies at the shelter are vaccinated.

Why: Those puppies are dogs at the shelter, and all of those dogs are vaccinated. So at least some puppies must be vaccinated.

Common Traps

Answers that are likely but not proven.
Answers that swap “some” for “most” or “all.”
Reversing a rule: “all dogs are vaccinated” does not mean all vaccinated animals are dogs.
Using outside knowledge.

Must Be True Questions FAQ

Is Must Be True the same as Inference?

They are close. Both ask what the text supports. “Must be true” needs full proof, while “most strongly supported” can be a bit softer.

Should I look for a conclusion?

Usually not. These stems give you facts rather than an argument.

Why do modest answers often win?

Weak claims like “some” or “at least one” are easier to prove than strong ones.

See all Logical Reasoning question types, read the Logical Reasoning guide, and practice with LSAC’s free official PrepTests.