LSAT, Graduate admissions

Logical Reasoning

Logical Reasoning presents short arguments or sets of facts, usually a single paragraph, followed by one question that asks you to analyze, evaluate, or complete the reasoning. Because two of the three scored sections are Logical Reasoning, roughly two-thirds of the scored questions on the test come from this section type, which makes it the largest single lever on the final score. Each section contains about 24 to 26 questions in 35 minutes, so pacing and disciplined reading of the stimulus matter as much as logic itself.

Position: 1 of 3 sections
Time: 35 minutes
Topics covered: 6 topics in this guide

What is covered

Topics inside this section.

These topics describe the scope students most often review for this part of LSAT. Treat them as a study checklist rather than an exhaustive list of what a single exam form can sample.

Argument structure: Identifying the conclusion, the premises that support it, and the role of any intermediate claims or background information.
Assumptions and gaps: Necessary and sufficient assumption questions that ask what the argument depends on or what would guarantee its conclusion.
Strengthen and weaken: Selecting new information that most supports or most undermines an argument without restating it.
Flaws in reasoning: Recognizing common errors such as causal confusion, sampling problems, equivocation, and conditional-logic mistakes.
Inference and must-be-true: Drawing conclusions that follow with certainty from a set of statements, including conditional chains and quantified claims.
Paradox, principle, and parallel reasoning: Resolving apparent discrepancies, applying or identifying governing principles, and matching the structure of one argument to another.

Study tips

How to practice LR.

Section-specific guidance that follows from how this material is usually tested.

Learn to find the conclusion before anything else; most wrong answers are attractive only when the conclusion has been misread.
Categorize every practice question by type and keep a log of which types cost the most time or accuracy.
Practice full 35-minute sections regularly so that pacing decisions, including which questions to skip and return to, become automatic.
Review every missed question by writing out why each wrong answer is wrong, not only why the right answer is right.

Where this fits

Logical Reasoning is 1 of 3 sections in the LSAT guide. Use the full guide to balance it against everything else you have to review.

Back to the LSAT guide Official exam information

Sample LR questions

Practice questions, not yet expert-reviewed

Original practice questions written to the published framework for this section. No expert has reviewed them, and they are not taken from any official exam. Try each one before you open the answer.

Question 1Foundational
In an argument, what is the term for the claim that the premises are offered to support?
1. AThe premise
2. BThe conclusion
3. CThe assumption
4. DThe counterexample
Show answer
Answer: B. The conclusion
The conclusion is the claim being argued for, and premises are the reasons given for it. An assumption is an unstated claim the argument needs, which is why it is never the statement the premises openly support.
Key insight: Find the conclusion first; every other part of an argument is defined relative to it.
Question 2Foundational
True or false: a necessary assumption is a statement that must be true for an argument's reasoning to succeed, even though the argument never states it.
1. ATrue
2. BFalse
Show answer
Answer: A. True
Necessary assumption questions ask for an unstated claim the argument depends on, so denying that claim destroys the reasoning. A sufficient assumption is different: adding it would guarantee the conclusion, but the argument does not have to require it.
Key insight: Negate a candidate assumption; if the argument collapses, the assumption was necessary.
Question 3Intermediate
A columnist argues that because cities that added bike lanes recorded more cycling injuries, bike lanes make cycling more dangerous. What is the main flaw in that reasoning?
1. AIt ignores that more people may now be cycling, so the injury rate per cyclist could have fallen
2. BIt confuses a necessary condition with a sufficient one
3. CIt relies on an authority speaking outside their field
4. DIt assumes the very conclusion it sets out to prove
Show answer
Answer: A. It ignores that more people may now be cycling, so the injury rate per cyclist could have fallen
Raw injury counts rise when exposure rises, so more cyclists can produce more injuries even as each cyclist becomes safer. The argument needs rate data rather than totals, and it contains no conditional claim and no appeal to authority.
Key insight: When a count rises, ask whether the population producing it rose too.
Question 4Intermediate
What is the contrapositive of the statement 'If a bill passes, then it had majority support'?
1. AIf a bill had majority support, then it passed
2. BIf a bill did not pass, then it did not have majority support
3. CIf a bill did not have majority support, then it did not pass
4. DIf a bill passed, then it did not have majority support
Show answer
Answer: C. If a bill did not have majority support, then it did not pass
The contrapositive negates both parts and reverses their order, and it is always logically equivalent to the original statement. 'If a bill had majority support, then it passed' is the converse, and 'If a bill did not pass, then it did not have majority support' is the inverse; neither follows from the original.
Key insight: Contrapositive: flip the order and negate both sides. The converse alone is never valid.
Question 5Advanced
Which Logical Reasoning question type asks for the answer that best explains how two apparently conflicting facts can both be true?
1. AStrengthen
2. BResolve the paradox
3. CParallel reasoning
4. DMethod of reasoning
Show answer
Answer: B. Resolve the paradox
Paradox questions present a discrepancy and ask what would make both statements consistent, so the credited answer supplies a fact that dissolves the tension. Strengthen questions instead add support to a conclusion, and a paradox stimulus usually contains no conclusion at all.
Key insight: A paradox stimulus states facts rather than an argument, so you explain it instead of supporting it.

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Logical Reasoning