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LSAT Logical Reasoning: Sample Questions + Complete Guide

October 18, 2023
10 min read
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Reviewed by:

Former Head of Pre-Law Office, Northeastern University, & Admissions Officer, Brown University

Reviewed: 10/18/23

If you’re on the long, bumpy road to law school and want to know how to ace the LSAT logical reasoning section, this guide will tell you everything you need to know!

Female student studying from book

The logical reasoning (LR) section can be stressful and overwhelming. You’ll be expected to read complicated passages with words you’ve likely never seen before, deconstruct and understand them, and choose the correct answer out of choices that are just as confusing as the passages.  

If you’ve begun your LSAT prep and aren’t sure where to start for the LR section or can’t seem to figure out how to best tackle the questions, this guide has got you covered! 

We’ll break down the most common LR questions, share tried and true tips on how to nail the LSAT, and include practice questions and answers to put these tips to the test!

LSAT Logical Reasoning Section Format

Each LR LSAT question will have three parts: a passage, a question or task, and five multiple-choice questions.

You will have to complete at least one LR section comprised of 24-26 questions. If you get LR questions for the experimental section of the LSAT, you’ll have to do another set of 24-26 questions.

LSAT Logical Reasoning Question Types

Before delving into the 20 most common question types you’ll see on the LSAT LR section, it’s important to first understand what an argument consists of so you know how to properly deconstruct one!

What is an Argument?

These are the main parts of the arguments you’ll see on the LR section: 

Conclusion

Each argument will have a conclusion that all of the evidence in the passage will support. This is what the author is trying to argue and persuade the readers to accept.

Evidence

Also commonly called premises, these are the supporting details that back up the author’s conclusion. 

Sub-conclusions

More complicated LSAT questions will have a sub-conclusion that can easily be mistaken as the main conclusion. This sub-conclusion will act as both evidence and a conclusion. It will be supported by some evidence but will ultimately work to prove the main conclusion. 

Background Information

Each passage will also provide some background information that will essentially be useless to you as it will never hold any important context. 

Now, let’s move on to the question types!

Find the Conclusion

Find the conclusion questions will ask you to identify the author’s main argument in a given passage. To accurately answer this question, ensure you find the statement that has the most evidence but doesn’t support any claim itself. 

These questions will generally look like:

  • “Which one of the following most accurately expresses the conclusion drawn in this argument?”
  • “The conclusion drawn in Mary’s argument is…”

Most Strongly Supported 

Most strongly supported questions will ask you to find the answer choice that is supported the most by the information in the passage. In other words, using only the information provided in the passage, which choice has enough evidence to be true? 

You may also be asked which choice is least supported by the passage.

Sample Strongly Supported questions are:

  • “Which of the following is most strongly supported by the information above?”
  • “Which of the following most logically completes the argument?”
  • “Which of the following can be most reasonably concluded from the information above?”
  • “Which of the following claims can most justifiably be rejected on the basis of the claims above?”

Find the Disagreement

These questions will involve questions that have two speakers sharing their opinions on a topic. You will be asked to find a claim both speakers would either agree or disagree with.

Both speakers must have an opinion on the statement in the correct choice. If one speaker does not express an opinion, then that answer choice cannot be true. 

Find the Disagreement question examples are:

  • “Kim and John disagree over/on whether…”
  • “Based on their statements, Lola and Hailey agree that…”

Find the Technique

For Find the Technique questions, you have to focus on the way the argument is constructed and how the author gets their point across. What techniques do they use to make their argument? 

These questions will be similar to the following samples:

  • “Lyla responds to Jack’s claim using which of the following argumentative techniques?”
  • “Which of the following is a reasoning technique used in the argument?”

Role Call

For Role Call questions, you’ll be identifying the role a certain statement plays in the overall passage. Depending on the statement, it might be evidence, background information, or the main conclusion.

Examples of these questions are:

  • “The claim that… is used in the argument to…”

Pinpoint the Principle

These questions will ask you to identify the principle used in the passage. You may be asked to identify the principle that justifies the argument or the principle that’s illustrated in the passage. 

These principles will be specific to the passage, not universal principles.

Pinpoint the Principle questions will follow this format:

  • “The argument’s reasoning most closely conforms to which of the following principles?”
  • “Which one of the following principles, if valid, most helps justify the reasoning in the argument above?”

Match the Structure

These questions are amongst the hardest and longest LR questions. Match the Structure questions require you to look at the given passage and see which answer choice has the same structure. Each answer choice will be its own passage.

This structure can refer to the type of reasoning used or how the argument is presented. The correct answer will have the same kind of evidence and the same kind of conclusion as the passage. 

Sample Match the Structure questions are:

  • “Which one of the following arguments is most similar in its reasoning to the argument above?”
  • ​​“Which one of the following arguments is most similar in its reasoning to the argument above?”

Match the Principles

Similar to Match the Structure questions, match the principle questions require you to find the answer choice that uses the same principle as the argument in the passage.

These questions will typically look like this:

  • “The principle underlying the above argument is most similar to the principle underlying which one of the following arguments?”

Find the Flaw

Find the Flaw questions will ask you to deduce the flaw in the argument presented in the passage. Is the author mistaking correlation for causation? Are they making a generalization? Are they attacking someone’s opinion based on their character? 

Consider common fallacies when reading the passage.

Find the Flaw question examples are:

  • “Which one of the following most accurately describes a flaw in the argument’s reasoning?
  • “The argument’s reasoning is questionable in that the argument…”

Match the Flaws

For these questions, you will have to figure out which answer choice has the same flaw as the one in the passage. 

The question stems for these types of questions will look like this:

  • “The flawed pattern of reasoning in the argument above is most similar to that in which of the following?”

Necessary Assumptions

Throughout your LSAT prep you’ll come across the terms necessary and sufficient conditions or assumptions. Necessary assumptions are those that must occur in order for the argument to work. This assumption will not be explicitly stated in the passage, so your job will be to figure out what is being assumed in order for the argument to be true.

Without this assumption, the entire argument would be undermined. 

Necessary Assumption questions typically follow this format:

  • “Which of the following is an assumption required by the argument?”
  • “The argument requires the assumption that”

Sufficient Assumptions

With a focus on language, sufficient assumptions are just that – sufficient enough to make the argument logically valid if added to it. In other words, the conclusion can be drawn logically if this assumption is made. This sufficient assumption will bridge the gap between the evidence and conclusion to complete the argument. 

Examples of the types of questions are:

  • “The conclusion drawn above follows logically if which one of the following is assumed?”
  • “The conclusion of the argument is strongly supported if which one of the following is assumed?”

In case you’re still having a hard time understanding the difference between a necessary and sufficient assumption, here is an example to clarify:

Let’s say you want to guarantee you can buy a $10 shirt that’s on sale. A necessary assumption would be that you have $1, and a sufficient assumption would be that you have $20. This sufficient assumption is not necessary because you could have less money and still be able to buy the shirt but $20 is enough to guarantee the purchase. 

On the other hand, $1 is necessary to buy a $10 shirt but is not sufficient to do so. Without at least $1, however, the entire guarantee is undermined. 

Strengthen and Weaken Questions

Strengthen questions will ask you to choose the answer choice that, if true, would most strengthen or weaken the argument being made. The correct answer choice will make the conclusion more or less likely to happen, depending on the type of question.

Sample Strengthen or Weaken questions are: 

  • “Which one of the following, if true, most strengthens/weakens the argument?”

Helping Hand

For Helping Hand questions, you’ll have to identify which choice would be the most helpful to evaluate the argument. These are similar to Strengthen questions because the correct answer will make the argument more concrete.

You may also be asked which answers are the least helpful to know! Either way, the question stems will look similar to these examples:

  • “Which of the following would be most useful to know in order to evaluate the argument?”
  • “The answer to which one of the following would least help in evaluating the argument?”

Explanations

These questions will ask you to find the answer that best explains a situation in the passage. These are not meant to be confused with Strengthen questions, as they are not trying to help the argument on a whole but create a logical explanation for a part of the argument.

Examples of these types of questions are:

  • “Which one of the following, if true, most helps to explain the preference described above?”
  • “Which one of the following, if true, contributes to an explanation of the difference in opinions presented?”

Resolutions

For Resolution questions, you will be trying to find the solution to a discrepancy described in the passage. 

Resolution questions will follow this type of format:

  • “Which one of the following, if true, most helps to resolve the apparent conflict described above?”
  • “Which one of the following, if true, most helps to resolve the discrepancy in the argument above?”
Male student studying for the LSAT

Logical Reasoning Sample Questions and Answers

Now that we’ve gone over the common questions you’ll see on the LSAT, here are some sample LSAT LR practice questions and their answers.

Question One

Laird: Pure research provides us with new technologies that contribute to saving lives. Even more worthwhile than this, however, is its role in expanding our knowledge and providing new, unexplored ideas.

Kim: Your priorities are mistaken. Saving lives is what counts most of all. Without pure research, medicine would not be as advanced as it is.

Laird and Kim disagree on whether pure research

  1. derives its significance in part from its providing new technologies
  2. expands the boundaries of our knowledge of medicine
  3. should have the saving of human lives as an important goal
  4. has its most valuable achievements in medical applications
  5. has any value apart from its role in providing new technologies to save lives

Answer and Explanation

The correct answer to this question is D. Laird argues pure research’s most valuable purpose is to expand knowledge, whereas Kim argues its most valuable purpose is in medical application to save lives. 

Option D is correct because Kim would agree with it, and Laird would disagree.

Question Two

During the construction of the Quebec Bridge in 1907, the bridge’s designer, Theodore Cooper, received word that the suspended span being built out from the bridge’s cantilever was deflecting downward by a fraction of an inch (2.54 centimeters).

Before he could telegraph to freeze the project, the whole cantilever arm broke off and plunged, along with seven dozen workers, into the St. Lawrence River. It was the worst bridge construction disaster in history.

As a direct result of the inquiry that followed, the engineering “rules of thumb” by which thousands of bridges had been built around the world went down with the Quebec Bridge. Twentieth-century bridge engineers would thereafter depend on far more rigorous applications of mathematical analysis.

Which one of the following statements can be properly inferred from the passage?

  1. Bridges built before about 1907 were built without thorough mathematical analysis and, therefore, were unsafe for the public to use.
  2. Cooper’s absence from the Quebec Bridge construction site resulted in the breaking off of the cantilever.
  3. Nineteenth-century bridge engineers relied on their rules of thumb because analytical methods were inadequate to solve their design problems.
  4. Only a more rigorous application of mathematical analysis to the design of the Quebec Bridge could have prevented its collapse.
  5. Prior to 1907 the mathematical analysis incorporated in engineering rules of thumb was insufficient to completely assure the safety of bridges under construction.

Answer and Explanation

E is the correct answer because it is the only choice that makes a logical inference based on the information presented. The passage indicates that the Quebec Bridge disaster occurred in 1907 and caused the engineering “rule of thumbs” to stop being used. 

As such, it can be inferred that this 1907 disaster bridge, and the ones before it, used the rule of thumbs and that these rules were insufficient to completely assure the safety of the bridges since the Quebec bridge collapsed. 

Question Three

The supernova event of 1987 is interesting in that there is still no evidence of the neutron star that current theory says should have remained after a supernova of that size. 

This is in spite of the fact that many of the most sensitive instruments ever developed have searched for the tell-tale pulse of radiation that neutron stars emit. Thus, current theory is wrong in claiming that supernovas of a certain size always produce neutron stars.

Which one of the following, if true, most strengthens the argument?

  1. Most supernova remnants that astronomers have detected have a neutron star nearby.
  2. Sensitive astronomical instruments have detected neutron stars much farther away than the location of the 1987 supernova.
  3. The supernova of 1987 was the first that scientists were able to observe in progress.
  4. Several important features of the 1987 supernova are correctly predicted by the current theory.
  5. Some neutron stars are known to have come into existence by a cause other than a supernova explosion.

Answer and Explanation

The correct answer to this question is B. The main argument being made is that current theory that claims that supernovas of a certain size always produce neutron stars is wrong. The proof used to support this claim is that the supernova event of 1987 has no evidence of a neutron star even after sensitive instruments searched for it. 

Answer B bridges a gap in this evidence by proving that these sensitive instruments have detected neutron stars much further away, demonstrating it wasn’t simply an error in the technology or range limitations that failed to detect a neutron star. 

Question Four

Political scientist: As a political system, democracy does not promote political freedom. There are historical examples of democracies that ultimately resulted in some of the most oppressive societies. Likewise, there have been enlightened despotisms and oligarchies that have provided a remarkable level of political freedom to their subjects.

The reasoning in the political scientist’s argument is flawed because it

  1. confuses the conditions necessary for political freedom with the conditions sufficient to bring it about    
  2. fails to consider that a substantial increase in the level of political freedom might cause a society to become more democratic
  3. appeals to historical examples that are irrelevant to the causal claim being made
  4. overlooks the possibility that democracy promotes political freedom without being necessary or sufficient by itself to produce it
  5. bases its historical case on a personal point of view

Answer and Explanation

D is the correct response. The argument fails to recognize that even if democracy is not sufficient for political freedom, it can still promote political freedom by contributing to it in most instances. 

Likewise, even if democracy is not necessary for political freedom, it can still be true that democracy is something that promotes political freedom wherever it is found.

Question Five

About two million years ago, lava dammed up a river in western Asia and caused a small lake to form. The lake existed for about half a million years. Bones of an early human ancestor were recently found in the ancient lake-bottom sediments that lie on top of the layer of lava. Therefore, ancestors of modern humans lived in western Asia between two million and one-and-a-half million years ago.

Which one of the following is an assumption required by the argument?

  1. There were no other lakes in the immediate area before the lava dammed up the river.
  2. The lake contained fish that the human ancestors could have used for food.
  3. The lava that lay under the lake-bottom sediments did not contain any human fossil remains.
  4. The lake was deep enough that a person could drown in it.
  5. The bones were already in the sediments by the time the lake dried up.

Answer and Explanation

E is the assumption required by the argument, and it is the only one that is directly relevant to the argument at hand. If the bones weren't initially in the sediment as the lake dried up, it implies they must have entered the sediment at a later time, specifically less than one-and-a-half million years ago. 

However, this would mean that the bones wouldn't serve as evidence for the presence of human ancestors in western Asia between two million and one-and-a-half million years ago. In other words, if E is false, the argument's conclusion wouldn't be valid!

How to Prepare for the LSAT Logical Reasoning Section

The best way to prepare for the LR section is to first become familiar with the common question types. Some of these questions, like Strengthen and Helping Hand questions, look similar but are not. By knowing each question type, you’ll have a better idea of what to look for in the answer choices.

You should also begin with a diagnostic test to assess your baseline abilities before creating a comprehensive study schedule. This schedule should involve as many LR practice questions as possible under timed conditions. These will help you develop good problem-solving strategies to answer the questions easier!

How to Answer Logical Reasoning Section in LSAT

Speaking of tips and tricks, here are our top tips on how to enhance your logical reasoning skills on the LSAT  and be prepared for test day!

Read the Question First

Read the question first instead of the passage to avoid having to re-read the passage to find what you’re looking for.

Don’t Make Unsupported Assumptions

Any inferences you make must be made directly from the passage. If the right answer goes against everything you know but logically follows the information in the passage, it is correct regardless of your own opinions or knowledge. 

Skip Questions

Don’t fixate on hard questions for too long. If you find yourself getting stuck on a question, move on to the next and come back to it if you have time. Answer as many questions as you can and then guess on any you don’t have time to finish. You should never leave a question blank because you still have a chance of guessing correctly.

Read Carefully

Misreading just one or two words can cost you several points on the LSAT. Ensure you are an active and engaged reader throughout your exam. For the LR section, in particular, keep track of the type of language being used. 

For instance, words like “never” and “always” are very strong words, which will likely be repeated in the correct answer choice and weakened to “sometimes” or “most of the time” in the incorrect choices. 

Additionally, you always want to look out for words like EXCEPT, which will always be bolded.

Don’t Focus on the Vocab

The questions in the LR section often use complicated terms and topics because it easily psychs students out. Do your best to focus on the arguments, not the vocab. If there are words you don’t understand, just replace them with words you do! The exact words themselves aren’t important, just the argument itself and its structure. 

FAQs

For any remaining questions about the logical reasoning questions on the LSAT read on to find your answers.

1. How Do I Ace Logical Reasoning on the LSAT?

You should familiarize yourself with the common question types you’ll see so you know how to best answer them and practice these questions under timed conditions using real past LSAT tests. Remember, you won’t have any aids or notes on test day! You’ll only have your knowledge and practice to rely on. 

2. What Percentage of the LSAT is Logical Reasoning?

The logical reasoning section takes up 25% or 50% of the LSAT, depending on whether you get an LR section for the experimental part of the LSAT. Considering this, it’s essential you do well on this section to avoid having to retake this costly exam

3. How Many Logical Reasoning Questions on LSAT?

There will be at least 24-26 logical reasoning questions on the LSAT. If you get logical reasoning questions for the experimental section of the LSAT, you’ll have to do another set of 24-26 questions.

4. What Is the Hardest Section of the LSAT?

The analytical reasoning section of the LSAT is generally considered to be the hardest.

5. Is Logical Reasoning On the LSAT?

Yes, you will see at least one logical reasoning section on the LSAT.

Acing the LSAT

LSAT study prep can be daunting and difficult! But, with this guide, and the additional support of experts who know how to increase your LSAT score by 12 points, you should be able to ace the LSAT logical reasoning section and get one step closer to achieving all of your career aspirations!

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