LSAT Strengthen Questions With Answers Practice Questions with Answers

LSAT Strengthen Questions With Answers Practice Questions with Answers

Logic games and reading comprehension often grab the headlines, but logical reasoning sections comprise roughly half of your scored LSAT Prep performance. Among these, the ability to bolster an argument's validity is a core skill tested by the Law School Admission Council. LSAT strengthen questions with answers practice questions with answers provide the necessary repetition to internalize the mechanical process of identifying and closing logical gaps. By learning to recognize common fallacies and strengtheners, you can turn one of the most frequent question types into a reliable source of points on test day.

Concept Explanation

LSAT strengthen questions require you to select the one answer choice that provides the most support for the conclusion of a given argument. These questions typically present a stimulus consisting of premises and a conclusion, where the connection between the two is logically fragile or contains a specific assumption. Your task is not to make the argument perfect, but to find the piece of information that makes the conclusion more likely to be true than it was before. This often involves addressing a potential weakness, providing additional evidence for a causal claim, or validating a necessary assumption. Key phrases in the prompt usually include "most strengthens," "most strongly supports," or "provides the most support for the argument above."

To tackle these effectively, follow this systematic approach:

1. Identify the Conclusion and Premises: Clearly separate what the author is trying to prove from the evidence provided.
2. Find the Logical Gap: Look for the "missing link" or the assumption the author is making. Often, the conclusion introduces a new concept not fully explained by the premises.
3. Predict the Answer: Think of a way to bridge that gap or eliminate a potential counter-objection.
4. Evaluate the Choices: Select the answer that provides the strongest positive impact on the relationship between the premises and the conclusion.

It is important to remember that in strengthen questions, the information in the answer choices is accepted as true. You are evaluating the impact of that new information on the existing argument. This differs from other question types where you might be analyzing the internal structure of the text itself. For more targeted practice on different reasoning styles, you might also find hard GRE reading exam questions useful for developing general analytical skills.

Solved Examples

1. The Causal Strengthener
   Stimulus: A recent study found that children who play chess score higher on standardized math tests. Therefore, playing chess improves a child's mathematical ability.
   Question: Which of the following, if true, most strengthens the argument?
   Solution:
   1. The conclusion claims a causal relationship: Chess (A) causes Math Skills (B).
   2. A common way to strengthen a causal claim is to eliminate an alternative cause or show that when the cause is absent, the effect is also absent.
   3. An answer like "Children with high math scores do not tend to seek out chess more than children with low scores" would strengthen the argument by ruling out reverse causality (B causing A).
2. The Comparison Strengthener
   Stimulus: Company X switched to a four-day work week and saw a 20% increase in productivity. Thus, any company that switches to a four-day work week will see a similar increase in productivity.
   Question: Which of the following most strengthens the argument?
   Solution:
   1. The argument assumes Company X is representative of "any company."
   2. To strengthen this, we need to show that Company X is not unique or that the conditions of the switch are universally applicable.
   3. The correct answer might be: "Company X's employees represent a wide variety of industries and job functions similar to those found in most other companies."
3. The Gap-Filler
   Stimulus: The city's new recycling program has failed to reduce the amount of waste sent to landfills. This is clearly because the citizens are not properly sorting their plastics.
   Question: Which of the following most strengthens the argument?
   Solution:
   1. The premise is the failure to reduce waste; the conclusion blames plastic sorting.
   2. The gap is the assumption that plastics make up a significant enough portion of the waste to cause this failure.
   3. A strengthener would be: "Plastics constitute the largest single category of waste sent to the city's landfills." This validates that sorting them would actually make a difference.

Practice Questions

1. Researchers observed that patients who took Vitamin D supplements had fewer respiratory infections than those who did not. They concluded that Vitamin D directly boosts the immune system's ability to fight viruses. Which of the following most strengthens the argument?
2. The local library's attendance has dropped by 30% since the opening of a new coffee shop across the street. The head librarian claims the coffee shop's free Wi-Fi is drawing away the library's patrons. Which of the following most strengthens the librarian's claim?
3. A tech firm found that software developers who use standing desks produce 15% fewer coding errors. The management decided to buy standing desks for all employees to increase overall software quality. Which of the following most strengthens the management's plan?

4. Economist: The recent increase in the minimum wage in City A led to a decrease in the total number of hours worked by entry-level employees. Therefore, the minimum wage increase caused a rise in local unemployment. Which of the following most strengthens the economist's argument?
5. Biologist: The population of songbirds in the valley has declined because the local cat population has doubled. To save the birds, we must reduce the number of cats. Which of the following most strengthens the biologist's argument?
6. A study showed that people who drink green tea daily have a lower risk of heart disease than those who do not. The researchers concluded that the antioxidants in green tea protect the heart. Which of the following most strengthens the conclusion?
7. The university's new policy requiring all freshmen to live on campus is intended to improve graduation rates. Data shows that students who live on campus are more likely to participate in study groups. Which of the following most strengthens the link between the policy and the goal?
8. A manufacturer claims that their new engine oil reduces engine wear by 50%. This claim is based on a test where cars using the new oil were driven for 100,000 miles without significant engine damage. Which of the following most strengthens the manufacturer's claim?
9. Political Analyst: Candidate Smith lost the election because she did not spend enough money on television advertisements in rural areas. Which of the following most strengthens the analyst's conclusion?
10. Archaeologists found charred grains at a site dating back 10,000 years. They concluded that the inhabitants of the site were practicing organized agriculture rather than just gathering wild grains. Which of the following most strengthens the archaeologists' conclusion?

Answers & Explanations

1. Answer: A study of patients with similar lifestyles showed that those who stopped taking Vitamin D saw an increase in infections.
   Explanation: This strengthens the causal claim by showing that when the cause (Vitamin D) is removed, the effect (protection from infection) also disappears.
2. Answer: A survey of coffee shop patrons revealed that 80% of them previously used the library for its internet access.
   Explanation: This provides a direct link between the coffee shop's offering and the library's lost patrons, supporting the librarian's specific causal claim.
3. Answer: The coding errors were not caused by factors that standing desks cannot address, such as lack of sleep or experience.
   Explanation: By ruling out other potential causes for the error reduction, this strengthens the claim that the desks themselves are the beneficial factor.
4. Answer: The decrease in hours worked was not accompanied by an increase in the number of employees hired.
   Explanation: This strengthens the link between "fewer hours" and "unemployment" by ensuring the work wasn't just spread across more people.
5. Answer: Other factors known to affect songbird populations, such as habitat loss or pesticide use, remained constant during the period.
   Explanation: This rules out alternative explanations, leaving the cat population as the most likely primary cause.
6. Answer: Lab tests on human heart cells showed that the specific antioxidants found in green tea prevent cellular damage.
   Explanation: This provides a biological mechanism that explains how the green tea achieves the effect, strengthening the causal link.
7. Answer: Participation in study groups is one of the strongest predictors of timely graduation at the university.
   Explanation: This bridges the gap between the intermediate step (study groups) and the ultimate goal (graduation rates).
8. Answer: The cars used in the test were subjected to harsh driving conditions that typically cause significant wear in less than 50,000 miles.
   Explanation: This shows the test was rigorous and that the oil performed better than standard expectations, validating the 50% claim.
9. Answer: In similar districts where Candidate Smith's opponent spent less on TV ads, Candidate Smith won by a large margin.
   Explanation: This acts as a control group, suggesting that the advertising spend was indeed the deciding factor in the loss.
10. Answer: The grains found were of a species that requires consistent irrigation and soil preparation to grow.
    Explanation: Since irrigation and soil prep are hallmarks of "organized agriculture," this evidence directly supports the conclusion over the "wild gathering" alternative.

Frequently Asked Questions

What is the difference between a strengthen question and a sufficient assumption question?

A strengthen question asks for any information that makes the conclusion more likely, whereas a sufficient assumption question requires an answer that, if true, would make the conclusion 100% logically certain. Strengthening is a lower bar of support than proving.

Can an answer choice strengthen an argument if it only adds a small amount of support?

Yes, the LSAT requires you to find the choice that "most" strengthens the argument among the options provided. Even a minor piece of evidence is a correct answer if the other four choices do nothing or weaken the argument.

How do I handle strengthen questions with causal reasoning?

Focus on either ruling out an alternative cause, showing that the cause and effect occur together, or showing that when the cause is absent, the effect is also absent. You can also use the AI Question Generator to practice specific causal scenarios.

Do I need to look for the "perfect" answer?

No, you are looking for the "best" answer among the five provided. Sometimes the correct answer is not what you predicted, but it is still the only one that provides any logical support to the conclusion.

Why are some strengthen answers so specific or seemingly narrow?

Specific evidence can often close a very specific logical gap. If an argument relies on a narrow assumption, a narrow and specific answer choice is often exactly what is needed to validate that assumption and strengthen the whole structure.