Easy LSAT Must Be True Questions With Answers Practice Questions

Easy LSAT Must Be True Questions With Answers Practice Questions

Logical reasoning accounts for approximately 50% of your scored performance on the modern Law School Admission Test (LSAT). Among the various question types you will encounter, Must Be True (MBT) questions are foundational, requiring you to identify a statement that is 100% guaranteed by the provided text. These questions test your ability to distinguish between what is likely and what is absolutely certain based on a specific set of premises.

Concept Explanation

An LSAT Must Be True question is a logical reasoning task that asks you to select the one answer choice that is logically proven by the information in the stimulus. Unlike other question types where you might look for a flaw or a way to strengthen an argument, MBT questions treat the stimulus as a set of facts that cannot be disputed. Your goal is to find a conclusion that is a direct consequence of those facts. To succeed, you must avoid "could be true" traps—statements that seem plausible or likely but are not strictly guaranteed. Success on these questions often involves identifying conditional relationships, such as $A \rightarrow B$, and recognizing the contrapositive $eg B \rightarrow eg A$ as a valid inference. Using tools like an AI Exam Simulator can help you practice these formal logic structures in a timed environment.

Effective preparation for this section starts with understanding the LSAT Prep fundamentals. In Easy LSAT Must Be True Questions With Answers, the logical leaps are usually small. You will often see simple restatements of the text or basic combinations of two sentences. For example, if the text says "All dogs are mammals" and "Buddy is a dog," the must-be-true conclusion is "Buddy is a mammal." You must remain within the "four corners" of the stimulus, meaning you should never bring in outside information or common sense assumptions that aren't explicitly stated.

Solved Examples

1. Stimulus: Every student who attends the gala must wear a tuxedo. Marcus attended the gala.
   Question: Which one of the following must be true?
   Solution:
   1. Identify the conditional rule: $\text{Gala} \rightarrow \text{Tuxedo}$.
   2. Apply the fact: Marcus was at the Gala.
   3. Draw the inference: Marcus wore a tuxedo.
   4. Answer: Marcus wore a tuxedo.
2. Stimulus: If the temperature drops below freezing, the pipes will burst. The pipes in the basement did not burst.
   Question: Which one of the following must be true?
   Solution:
   1. Identify the rule: $\text{Freezing} \rightarrow \text{Burst}$.
   2. Identify the contrapositive: $eg \text{Burst} \rightarrow eg \text{Freezing}$.
   3. Apply the fact: The pipes did not burst ($eg \text{Burst}$).
   4. Answer: The temperature did not drop below freezing.
3. Stimulus: Most employees at the firm are lawyers. Some of the lawyers at the firm specialize in tax law.
   Question: Which one of the following must be true?
   Solution:
   1. Analyze the quantities: "Most" ($> 50\%$) and "Some" ($\geq 1$).
   2. Look for overlap: We know at least one person is both a lawyer and a tax specialist.
   3. Evaluate the certainty: We cannot say most are tax specialists, only that at least one tax specialist works at the firm.
   4. Answer: There is at least one tax specialist employed at the firm.

Practice Questions

1. All organic produce at the local market is grown within 50 miles of the city. Sarah bought a crate of organic tomatoes at the local market today.

2. If a laptop has a solid-state drive, it boots up in less than ten seconds. The new Zenith model boots up in fifteen seconds.

3. No member of the rowing team is allowed to skip morning practice. Jenkins is a member of the rowing team.

4. Many professional athletes follow a strict diet. Some people who follow a strict diet also take daily vitamins.

5. If it rains on Saturday, the outdoor concert will be moved to the gymnasium. The outdoor concert was not moved to the gymnasium.

6. All top-tier law schools require a high LSAT score for admission. University X is a top-tier law school.

7. Every time the alarm rings, the dog barks. The dog is currently sleeping quietly.

8. Only residents of the building are allowed to use the rooftop pool. Kevin is using the rooftop pool.

Answers & Explanations

1. Answer: The tomatoes Sarah bought were grown within 50 miles of the city.
   Explanation: The stimulus establishes a rule that all organic produce at that market meets the distance requirement. Since the tomatoes are organic and from that market, they must meet the requirement.
2. Answer: The new Zenith model does not have a solid-state drive.
   Explanation: This uses the contrapositive. If $\text{SSD} \rightarrow < 10 \text{s}$, then $\geq 10 \text{s} \rightarrow eg \text{SSD}$. Since 15 seconds is not less than 10, the laptop cannot have an SSD.
3. Answer: Jenkins is not allowed to skip morning practice.
   Explanation: This is a direct application of a universal rule to a specific individual. If no member can skip, and Jenkins is a member, Jenkins cannot skip.
4. Answer: There is at least one person who follows a strict diet and takes daily vitamins.
   Explanation: The word "some" in logic means "at least one." Since some people who follow the diet also take vitamins, it is a mathematical certainty that at least one such person exists.
5. Answer: It did not rain on Saturday.
   Explanation: If rain leads to a move, and no move occurred, we can conclude the sufficient condition (rain) did not happen.
6. Answer: University X requires a high LSAT score for admission.
   Explanation: University X belongs to the group "top-tier law schools," and every member of that group shares the trait of requiring a high LSAT score.
7. Answer: The alarm is not currently ringing.
   Explanation: If the alarm ringing forces the dog to bark, and the dog is quiet, the alarm cannot be ringing. This is the contrapositive of the original statement.
8. Answer: Kevin is a resident of the building.
   Explanation: The phrase "only residents" indicates that being a resident is a necessary condition for using the pool. Since Kevin is using the pool, he must satisfy that condition.

To further sharpen your skills, you might explore reading comprehension strategies or use a flashcard generator to memorize logical indicators like "only if" and "unless."

Frequently Asked Questions

What is the difference between "Must Be True" and "Most Strongly Supported"?

A Must Be True question requires a 100% logical guarantee, whereas Most Strongly Supported allows for the most likely answer based on the evidence. In MBT questions, even a 1% chance of the answer being false makes it incorrect.

Can I use outside knowledge for LSAT Must Be True questions?

No, you must strictly limit your reasoning to the information provided in the stimulus. Even if a statement is factually true in the real world, it is wrong on the LSAT if the text doesn't prove it.

How do I identify a Must Be True question?

Look for stems that use phrases like "Which one of the following must be true," "Which of the following can be properly inferred," or "Which one of the following follows logically." These phrases signal that you are looking for a deduction.

What are common trap answers in Easy LSAT Must Be True Questions With Answers?

Common traps include "Could Be True" answers, which are possible but not certain, and "Exaggerated" answers that use stronger language (like "all") than the stimulus supports (like "some").

Should I diagram every Must Be True question?

Diagramming is most helpful when the stimulus contains multiple conditional statements ($A \rightarrow B, B \rightarrow C$). For simpler questions, a mental check of the logic is usually sufficient to save time.

Is the contrapositive always a Must Be True inference?

Yes, the contrapositive of any valid conditional statement is logically equivalent to the original and is a very common correct answer in Must Be True sets. If the stimulus provides $X \rightarrow Y$, then $eg Y \rightarrow eg X$ is always true.