LSAT Logical Reasoning Practice Set 2 Practice Questions with Answers

Twenty-five questions typically constitute a single section of the Logical Reasoning portion of the LSAT, making speed and accuracy vital. Success on this exam requires more than just intuition; it demands a systematic approach to deconstructing arguments, identifying flaws, and recognizing logical patterns. By engaging with this LSAT Logical Reasoning Practice Set 2, you will refine your ability to parse complex stimuli and select the most logically sound answer choices under pressure.

Concept Explanation

LSAT Logical Reasoning evaluates your ability to analyze, evaluate, and complete arguments by identifying the relationships between premises and conclusions. At its core, every LSAT Prep strategy focuses on identifying the "stimulus" (the passage), the "question stem" (the task), and the "answer choices." Most questions revolve around an argument, which is a set of statements (premises) intended to provide support for another statement (the conclusion). To excel in this section, you must distinguish between valid deductions, where the conclusion must follow from the premises, and inductive arguments, where the premises only make the conclusion more likely.

Common question types in this practice set include:

• Strengthen/Weaken: Finding information that supports or undermines the connection between the premise and conclusion.

• Assumption: Identifying unstated premises that are necessary for the argument to hold true.

• Flaw in Reasoning: Recognizing logical errors such as circular reasoning, correlation vs. causation, or formal fallacies.

• Inference: Determining what must be true based strictly on the provided information.

According to the Law School Admission Council (LSAC), these questions test skills essential to legal analysis, such as drawing well-supported conclusions and identifying relevant information. Utilizing tools like an AI Question Generator can help you simulate the variety of scenarios found on the actual exam.

Solved Examples

1. Example: Identify the Flaw
   Stimulus: Every time the local basketball team wears their blue jerseys, they win. Therefore, the blue jerseys must possess some lucky quality that causes the team to play better.
   Solution:

   1. Identify the conclusion: The blue jerseys cause the team to win.

   2. Identify the premise: There is a correlation between wearing the jerseys and winning.

   3. Detect the flaw: The argument assumes correlation implies causation. It ignores other factors (like playing weaker opponents when wearing blue).

   4. Correct Answer: The argument confuses a temporal coincidence with a causal relationship.

2. Example: Necessary Assumption
   Stimulus: To be eligible for the scholarship, a student must have a GPA above 3.8. Since Sarah was awarded the scholarship, she must have studied at least four hours every day.
   Solution:

   1. Identify the conclusion: Sarah studied at least four hours every day.

   2. Identify the premise: Sarah got the scholarship (which requires a 3.8 GPA).

   3. Find the gap: The argument assumes that the only way to get a 3.8 GPA is by studying four hours a day.

   4. Correct Answer: No student can achieve a GPA above 3.8 without studying at least four hours every day.

3. Example: Inference
   Stimulus: All mammals are warm-blooded. No cold-blooded creatures can survive in the Arctic tundra. Some mammals live in the Arctic tundra.
   Solution:

   1. Map the logic: Mammal $\rightarrow$ Warm-blooded. Arctic $\rightarrow$ Not Cold-blooded. Some Mammals $\in$ Arctic.

   2. Combine the facts: If some mammals are in the Arctic, and those in the Arctic are not cold-blooded, then those specific mammals are warm-blooded.

   3. Correct Answer: At least some warm-blooded creatures live in the Arctic tundra.

Practice Questions

1. Many people believe that drinking coffee leads to insomnia. However, a recent study showed that people who drink five cups of coffee a day report feeling more energetic than those who drink none. Therefore, coffee does not cause insomnia. Which of the following most accurately describes the flaw in the argument?

2. The city council plans to reduce traffic by increasing the price of city parking permits by 50%. This will definitely work, because when the price of gasoline rose by 50% last year, traffic decreased significantly. Which of the following, if true, most weakens the argument?

3. If the government increases taxes, consumer spending will decrease. If consumer spending decreases, the economy will enter a recession. The economy has not entered a recession. What can be logically concluded?

4. All successful entrepreneurs are risk-takers. Some risk-takers are also mountain climbers. Therefore, some successful entrepreneurs are mountain climbers. The reasoning in the argument is flawed because:

5. Nutritionist: "Eating processed sugar is the primary cause of tooth decay. Since my patient has no cavities, they must not eat processed sugar." The nutritionist’s argument is most similar in its flawed reasoning to which of the following?

6. A study of 1,000 professional athletes found that those who meditated for 20 minutes a day had 15% fewer injuries than those who did not. Thus, meditation prevents physical injury. Which of the following, if true, most strengthens the argument?

7. No one who is afraid of heights should become a pilot. All pilots must undergo rigorous training. Some people who undergo rigorous training are not afraid of heights. Which of the following must be true based on these statements?

8. The company president argued that the new software would increase productivity. However, the software costs $50,000 to implement, which is more than the projected profit increase for the first year. Therefore, the company should not buy the software. What is an unstated assumption of this argument?

Answers & Explanations

1. Answer: It confuses feeling energetic with the inability to sleep.
   The argument uses "feeling energetic" as evidence against "insomnia." However, one can feel energetic during the day and still suffer from insomnia at night. This is an error of equivocation or shifting terms.

2. Answer: Parking permit costs represent a much smaller fraction of total driving costs than gasoline.
   This weakens the analogy. If parking permits are cheap to begin with, a 50% increase might not change behavior, unlike a 50% increase in gasoline, which affects every mile driven.

3. Answer: The government did not increase taxes.
   This follows the law of modus tollens. If $P \rightarrow Q$ and $Q \rightarrow R$, then $P \rightarrow R$. If $\text{not } R$, then $\text{not } P$. Since there is no recession, taxes were not increased.

4. Answer: It assumes that two groups that both overlap with a third group must overlap with each other.
   Just because Entrepreneurs and Climbers both belong to the "Risk-taker" category doesn't mean they intersect. They could be two entirely separate subsets of risk-takers.

5. Answer: If it rains, the ground gets wet. The ground is not wet, so it did not rain.
   This is actually a valid argument form. The nutritionist’s original flaw is denying the antecedent or inverse error. A better match would be: "If you are a doctor, you are smart. You are not a doctor, so you are not smart."

6. Answer: The athletes who meditated did not engage in any other injury-prevention activities that the non-meditators avoided.
   This strengthens the argument by eliminating alternative causes for the reduced injury rate, isolating meditation as the likely cause.

7. Answer: Some people who undergo rigorous training are eligible to be pilots.
   Since all pilots undergo rigorous training, and some people who undergo that training are not afraid of heights (a requirement for being a pilot), it is possible for some in that group to be pilots.

8. Answer: A project's value should be judged solely on its first-year profit increase.
   The argument rejects the software based on first-year costs vs. first-year profits, ignoring long-term gains. It assumes the first year is the only relevant metric.

Frequently Asked Questions

What is the difference between a sufficient and a necessary assumption?

A sufficient assumption is a premise that, if added to the argument, would guarantee the conclusion is true. A necessary assumption is a statement that must be true in order for the argument to even be possible, often identified using the negation test.

How can I improve my speed on the LSAT Logical Reasoning section?

Improving speed requires mastering the identification of question types so you can apply specific strategies immediately. You can practice with a Retrieval Challenge to sharpen your memory of logical fallacies and common argument structures.

What is the "Negation Test"?

The Negation Test is a technique used for Necessary Assumption questions where you logically negate an answer choice. If the negated version of the choice destroys the argument's conclusion, then that choice is the correct necessary assumption.

Are formal logic symbols necessary for the LSAT?

While not strictly required, using symbols to represent conditional statements (e.g., $A \rightarrow B$) can help prevent errors in complex "Must Be True" or "Parallel Reasoning" questions. This shorthand allows for quicker visualization of the logical flow without getting bogged down in the text.

How many Logical Reasoning sections are on the current LSAT?

As of 2024, the LSAT consists of two scored Logical Reasoning sections, one scored Reading Comprehension section, and one unscored experimental section. This makes Logical Reasoning the most significant contributor to your overall score, as it accounts for roughly 50% of the graded material.

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