An LSAT logical reasoning example becomes useful only when you can explain why one answer works and why the others fail. The three original LSAT-style questions below show how to locate an argument’s conclusion, separate it from its evidence, identify a flaw, and eliminate answer choices efficiently. They are practice items, not released LSAT questions.
The basic method for every logical reasoning example
Before looking at the answers, reduce the stimulus to two parts:
- Evidence: the facts the speaker gives you.
- Conclusion: the claim the speaker wants you to accept.
Then ask one focused question: What would have to be true for this evidence to support that conclusion? For a flaw question, find the gap. For a strengthen question, look for an answer that narrows that gap. For a must-be-true question, use only what the statements require.
If recognizing question types is still slow, keep a LSAT Logical Reasoning question type cheat sheet nearby while you practice. The label tells you what job the correct answer must perform.
Example 1: Find the flaw in a causal argument
Question
A grocery store stopped displaying candy near its checkout counters. During the following month, sales of fruit cups increased. The store manager concludes that removing the candy display caused the increase in fruit-cup sales.
The manager’s reasoning is most vulnerable to criticism because it
A. assumes that every customer who bought a fruit cup had previously bought candy. B. treats an event that followed a change as though the change must have caused the event. C. fails to establish that fruit cups are more nutritious than candy. D. bases a conclusion about grocery stores on evidence from only one store. E. assumes that customers notice products displayed near checkout counters.
Answer: B
Step-by-step explanation
Evidence: The candy display was removed. Later, fruit-cup sales rose.
Conclusion: Removing the candy display caused the rise in fruit-cup sales.
The argument moves from sequence to causation: one thing happened, then another thing happened, so the first supposedly caused the second. But other explanations remain possible. The store may have discounted fruit cups, changed the weather-facing display, or experienced a seasonal shift in demand.
Answer B names that gap precisely. The manager treats “after” as proof of “because of.”
Why the other answers fail:
- A is too extreme. The conclusion does not require every fruit-cup buyer to have been a candy buyer.
- C raises a nutrition issue that is irrelevant to the causal claim.
- D criticizes the size of the sample, but the manager is drawing a conclusion about this store’s sales, not all grocery stores.
- E could make the manager’s explanation more plausible, but the argument does not assume every customer notices checkout displays.
A fast flaw-question habit is to restate the argument in plain language: “Fruit cups sold more after the display changed, therefore the display change did it.” Once the shortcut is visible, the correct answer is easier to spot. For more practice with this process, see how to approach LSAT flaw questions step by step, then run timed repetitions with PurrLearn’s LSAT logical reasoning flaw quiz, which explains the gap behind every answer.
Example 2: Draw a conclusion that must be true
Question
Every ceramicist is an artist. Some artists teach evening classes. No person who teaches evening classes is a full-time librarian.
If the statements above are true, which one of the following must also be true?
A. Some artists are not full-time librarians. B. Every artist is a ceramicist. C. Some ceramicists teach evening classes. D. No full-time librarian is an artist. E. Every teacher of an evening class is an artist.
Answer: A
Step-by-step explanation
Start with the statement that guarantees someone exists:
> Some artists teach evening classes.
So, at least one person is both an artist and an evening-class teacher. The third statement says that no evening-class teacher is a full-time librarian. That same person therefore is an artist who is not a full-time librarian.
That proves A.
The other choices add information the stimulus never supplies:
- B reverses the first rule. “Every ceramicist is an artist” does not mean every artist is a ceramicist.
- C assumes that ceramicists exist and that one teaches evening classes. Neither follows.
- D is too broad. The stimulus leaves open the possibility that some artists are full-time librarians, as long as they do not teach evening classes.
- E reverses the existential statement. We know some artists teach; we do not know that all teachers are artists.
This is a good reminder that “some” does not mean “all,” and a one-way rule cannot be reversed. When you work through formal-language questions, write only the relationship the sentence actually gives you.
Example 3: Strengthen the link between evidence and conclusion
Question
Students who completed a six-week tutoring course scored higher on a later practice test than they had scored before taking the course. The course director concludes that the tutoring course improves students’ test performance.
Which one of the following, if true, most strengthens the director’s conclusion?
A. Some students enrolled in the course because they enjoyed studying with classmates. B. The course director has taught test-preparation classes for many years. C. In a study, students randomly assigned to the course improved more than similar students assigned to no course. D. The practice test included questions from several different subject areas. E. Some students who did not take the course also improved on a later practice test.
Answer: C
Step-by-step explanation
Evidence: Course participants improved from one practice test to a later one.
Conclusion: The course caused the improvement.
The missing link is causation. Perhaps participants would have improved anyway through independent study, familiarity with the test, or extra motivation. A strong answer should compare participants with a relevant group that did not receive the course.
Answer C does exactly that. Random assignment makes the two groups more comparable, and the stronger improvement among course participants supports the claim that the course made a difference.
Why the others are weaker:
- A explains one possible reason students joined; it does not show the course caused improvement.
- B is about the instructor’s experience, not the course’s effect.
- D describes the test but does not connect the course to higher performance.
- E highlights an alternative explanation: scores can improve without the course.
For strengthen questions, do not look for an answer that proves the conclusion beyond doubt. Look for the one that makes the conclusion more likely by addressing its biggest weakness.
How to eliminate answer choices without guessing
When two answers seem plausible, name the task before comparing them. A flaw answer must describe a reasoning error. A strengthen answer must add support. A must-be-true answer must be forced by the stimulus.
Use this compact checklist:
- Restate the conclusion in a few words.
- Identify the evidence offered for it.
- Predict the gap before reading choices.
- Reject answers that are relevant but perform the wrong job.
- Be suspicious of extreme wording such as “every,” “never,” or “only” unless the stimulus requires it.
After each missed question, write one sentence explaining the gap. Avoid labels alone, such as “causation flaw.” A better note is: “The argument assumed the policy caused the later result without ruling out other changes.” That kind of review transfers to new questions.
For a larger set of worked items, use these LSAT logical reasoning questions and answers with full explanations. If flaws are your main weakness, a logical fallacies quiz with answers and printable practice can help you practice naming the gap quickly.
FAQ
What is the best way to start an LSAT logical reasoning question?
Read the stimulus first and identify its conclusion before looking at the answer choices. If there is no conclusion, the question may be asking what follows from a set of facts rather than asking you to evaluate an argument.
How do I tell evidence from a conclusion?
The conclusion is the point the speaker is trying to establish. Signal words such as “therefore,” “thus,” and “so” can help, but they are not required. Ask which statement the other statements are meant to support.
Should I diagram every logical reasoning question?
No. Diagram conditional statements when the wording requires precision, especially with “if,” “only if,” “unless,” “all,” and “none.” For ordinary causal or comparison arguments, a short plain-English summary is often faster.
Why are wrong answers often tempting?
Many wrong answers describe something related to the stimulus. Relevance is not enough. The correct answer must answer the specific question asked and match the exact gap or inference in the argument.
Conclusion
The most reliable way to learn from an LSAT logical reasoning example is to separate evidence from conclusion, predict the missing link, and test each answer against that link. Practice the explanation as carefully as the answer choice; that is where pattern recognition starts. When you can name the gap before reading the choices, prove it under a clock: the 12-question flaw quiz gives you instant feedback on every call.