How to Solve LSAT “Must Be True” Questions

In this article, we’ll guide you through the process of solving “Must Be True” questions, which appear in the LSAT Logical Reasoning section.

These questions require you to identify which statements are undeniably true based on the information provided in the passage. We’ll cover strategies for making accurate predictions and handling both short and long passages.

What are LSAT "Must Be True" Questions?

LSAT Must Be True questions ask you to identify which statement or conclusion is definitively true based on the information provided in the passage.

To solve a "Must Be True" question, you need to select the option that is 100% proven by the passage, either by directly restating the information given or by combining facts to make a new, indisputable inference.

Types of "Must be True" Questions

Here are some ways a question stem may ask you to figure out which answer choice must be true given what was said in the passage:

• If the statements above are true, which one of the following must be true?
• Which one of the following conclusions follows logically from the statements above?
• Which one of the following can be properly inferred from the passage above?
• Which one of the following statements can be properly concluded from the mayor’s statements?
• The above statements logically commit the executive to which one of the following conclusions?

Often there are several things that must be true. You might identify one or two inferences without seeing the one that they have in mind. That’s okay. As you read each answer choice, the only question you need to ask yourself is: “Does this answer have to be true?” The correct answer will be 100% proven by the evidence in the passage.

Make Your Best Prediction

Engage with the passage and ensure that you understand it. Then make a strong prediction.

Everything in the passage is evidence. The passage will usually be a series of facts. It might also have an argument. Don’t worry about real-world accuracy. Assume everything in the passage is true.

Based on that evidence, predict what else must be true. The best way to do this is to look for links between statements. Can you put them together to make a new inference?

For instance, if the passage says that “most vacations are expensive” and that “anything expensive is worth doing at least once,” you can infer that “most vacations are worth doing at least once.”

Long Passages

If the passage is long and convoluted, compare each answer choice with only the part of the passage that seems relevant to that answer. Then ask yourself: “Does this answer have to be true given what the passage says right here?”

Don’t ignore the other parts of the passage; just divide and conquer.

Short Passages

If the passage is comprised only of if-then statements, link them in your head. Diagramming on Logical Reasoning is a waste of time that often ends up confusing students more than the passage itself does. Get comfortable with making sense of the passage in your head and making commonsense connections between ideas that share a link.

Troubleshooting

The correct answer will either (1) restate something that was already said in the passage, or (2) combine two or more facts to make a new inference that is 100% proven by the passage.

Answer choices with weaker wording are generally easier to prove. Strongly worded statements rarely have to be true—unless the passage proves otherwise. In the example above, it’s easier to prove that “most vacations are worth doing at least once” than that “every single vacation is worth doing five or more times.” (Remember content is more important than word strength, so don’t use this technique as a crutch.)

More on Solving LSAT Must Be True Questions

What is a "Must Be True" question type?

A "Must Be True" question on the LSAT requires you to determine which statement or conclusion is undeniably true based on the information provided in the passage. These questions test your ability to infer conclusions that logically follow from the facts or arguments presented, without introducing any new assumptions or info. The right answer will be 100% supported by the evidence given in the passage.

What's the difference between "Must be True" and "Must Be False" questions in the LSAT?

The main difference between "Must Be True" and “Must Be False" questions is the focus of the logical requirement. "Must Be True" questions ask you to find a statement that's definitively supported by the passage, meaning it must be true based on the given information. In contrast, "Must Be False" questions require you to identify a statement that can't possibly be true given the information in the passage.

What is the difference between "Sufficient Assumption" and "Must Be True?"

"Sufficient Assumption" and "Must Be True" questions serve different functions in LSAT Logical Reasoning. "Sufficient Assumption" questions ask you to identify an assumption that, if true, would make the argument's conclusion logically valid. "Must Be True" questions require you to find a statement that is logically derived from the passage’s facts, without making any assumptions beyond what is provided. Essentially, "Sufficient Assumption" questions focus on making an argument win with a new idea, while "Must Be True" questions focus on identifying conclusions or premises that are already in the passage or are directly supported by it.