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Question 261Question →

Match each argument excerpt below with the abstract description of the logical flaw it commits.

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Items

A prominent neurosurgeon recently argued on a talk show that the country's shift toward flat-rate income taxation will stagnate economic growth. Given his undeniable brilliance and the high regard in which he is held, policymakers must abandon the flat-rate tax proposal.
The lead researcher funded by the Coalition of Sugar Refiners has published a report arguing that the new tax on sweetened beverages will cause massive job losses without improving public health. Given his detailed knowledge of the food industry, legislators should heed his warning and vote against the tax.
A recent survey of the region's voters reveals that almost three-quarters of them oppose the new restrictions on beachfront property development, viewing them as an unnecessary overreach. It is clear, therefore, that these restrictions are fundamentally unjust.
Unless the university administration approves the immediate restructuring of the athletics department, our recruitment numbers will plummet, our loyal coaching staff will face devastating layoffs just before the holidays, and the proud legacy of our alumni will be destroyed. Thus, the restructuring plan is the right decision.

Matches

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Answer

The neurosurgeon excerpt matches relying on an irrelevant expert; the sugar researcher excerpt matches basing a conclusion on a source with a vested interest; the voter survey excerpt matches treating widespread belief as evidence of truth; and the university athletics excerpt matches exploiting sympathies and anxieties.
Each excerpt exemplifies a distinct variant of an illegitimate appeal. The neurosurgeon excerpt appeals to an unqualified authority. The sugar researcher excerpt appeals to a biased authority, ignoring a clear conflict of interest. The voter survey excerpt commits an ad populum fallacy by equating popular opposition with objective injustice. Finally, the university excerpt relies entirely on emotional manipulation rather than presenting logically relevant evidence.

Step-by-Step Solution

1
Analyze the neurosurgeon excerpt.
Identified as an appeal to an unqualified authority.
It uses a medical professional's prestige to draw a conclusion about tax policy, which falls entirely outside their domain of expertise.
2
Examine the sugar researcher excerpt.
Identified as an appeal to a biased authority.
While the researcher has relevant knowledge, their funding from the sugar industry indicates an ulterior motive regarding a beverage tax.
3
Evaluate the voter survey excerpt.
Identified as an appeal to popular opinion (ad populum).
It uses the sheer popularity of an opinion to falsely prove that the restrictions are objectively unjust.
4
Assess the university administration excerpt.
Identified as an appeal to emotion.
Instead of providing relevant evidence for the restructuring, it relies on fear of layoffs and loss of legacy.

Key Concept

Appeal Fallacies (Authority, Emotion, Majority)
Question 262Question →

Below are four distinct arguments that rely on statistical, survey, or polling data. Each argument commits a specific methodological fallacy. Pair each argument with the abstract logical description that best characterizes its underlying vulnerability.

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Items

An educational task force evaluated the effectiveness of a demanding three-year academic acceleration program by assessing the standardized test scores of the students enrolled in their third year. Because 98 percent of these students scored in the top percentile, the task force concluded that the program drastically improves the academic performance of any student who enters it.
During a broadcast concerning proposed zoning regulations, a television news anchor directed viewers to participate in an online poll regarding the controversial legislation. Given that 85 percent of the respondents expressed vehement opposition, the network reported that the vast majority of the electorate rejects the zoning changes.
In order to estimate the average amount of sleep adults in a sprawling metropolis get per night, researchers interviewed patrons at several 24-hour coffee shops between the hours of 2:00 AM and 5:00 AM. They subsequently concluded that the typical adult in the metropolis sleeps fewer than five hours per night.
A political campaign distributed a questionnaire that asked, 'Do you support the incumbent's reckless economic policies that threaten to bankrupt our municipality?' Relying on the responses, the campaign manager declared that 90 percent of constituents oppose the incumbent's economic policies.

Matches

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Answer

The educational task force argument matches the survivorship bias description. The television news anchor argument matches the self-selection bias description. The sleep researchers argument matches the anomalous demographic subset description. The political campaign argument matches the loaded inquiry phrasing description.
Each argument commits a distinct sampling or survey flaw. The task force argument is flawed because it measures success only among those who survived a multi-year process (survivorship bias). The news poll is flawed because it relies on viewers motivated enough to respond, who rarely represent the broader population (voluntary response bias). The sleep study is flawed because surveying people at a coffee shop at 3:00 AM guarantees a sample of people with atypical sleep patterns (unrepresentative sample). The political survey is flawed because the loaded wording of the question forces respondents toward a particular answer (framing effect).

Step-by-Step Solution

1
Analyze the educational task force argument to identify its flaw.
The sample only tests third-year students in a demanding program.
This identifies survivorship bias, matching the description of excluding those who did not complete the process.
2
Analyze the television news anchor argument to identify its flaw.
The poll relies entirely on viewers choosing to call in.
This identifies self-selection or voluntary response bias, matching the description regarding groups whose members self-select.
3
Analyze the sleep researchers argument to identify its flaw.
The survey targets people awake at 3:00 AM at coffee shops.
This identifies an unrepresentative sample, matching the description of a demographic subset whose location and timing make them highly anomalous.
4
Analyze the political campaign argument to identify its flaw.
The survey question uses emotionally charged and loaded language.
This identifies a leading question flaw, matching the description of an inquiry designed to elicit a specific response.

Key Concept

Identifying Specific Types of Sampling and Survey Flaws in Logical Arguments
Estimated Time:3m 0s
Question 263Question →

In Logical Reasoning, the Negation Technique is used to test whether an assumption is truly necessary for an argument to hold. This technique requires accurately forming the logical negation of a candidate assumption statement. Match each assumption statement below with its exact logical negation.

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Items

All successful entrepreneurs are risk-takers.
Some new tax policies are beneficial.
No seasoned investors ignore market trends.
If the interest rate rises, inflation will decrease.

Matches

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Answer

The correct pairings are: 'All...' negates to 'At least one... is not...'; 'Some...' negates to 'No...'; 'No...' negates to 'At least one... is...'; and 'If A, then B' negates to 'A happens and B does not'.
Each assumption statement has been paired with its exact logical contradictory. A mathematically sound negation covers all remaining logical possibilities without going too far. For example, the negation of an 'all' claim simply requires one counterexample, and the negation of a conditional claim shows the sufficient condition occurring without the necessary condition.

Step-by-Step Solution

1
Identify the quantifier or logical structure in the first statement: 'All successful entrepreneurs...'
It is a universal affirmative. The exact logical negation is 'Not all' or 'At least one is not'. Match with 'At least one successful entrepreneur is not a risk-taker.'
Negating 'All' does not mean 'None'; it merely requires a single counterexample to make the original statement false.
2
Identify the quantifier in the second statement: 'Some new tax policies...'
It is an existential affirmative. The exact logical negation is 'None'. Match with 'No new tax policies are beneficial.'
If it is false that 'some' (at least one) policy is beneficial, then zero policies are beneficial.
3
Identify the quantifier in the third statement: 'No seasoned investors...'
It is a universal negative. The exact logical negation is 'Some' or 'At least one'. Match with 'At least one seasoned investor ignores market trends.'
If it is false that 'no one' does something, it must mean that at least one person does it.
4
Identify the logical structure of the fourth statement: 'If the interest rate rises...'
It is a conditional statement. The exact logical negation is that the trigger happens but the result does not. Match with 'The interest rate rises, and inflation does not decrease.'
A conditional statement is only violated when the sufficient condition (the 'if' clause) is met, but the necessary condition (the 'then' clause) fails to occur.

Key Concept

Logical negation involves producing a statement that must be false when the original is true, and must be true when the original is false, without overreaching.
Question 264Question →

Match each argument (stimulus) with the supporter assumption that is necessary to bridge the logical gap between its premise and its conclusion.

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Items

The proposed community center will feature state-of-the-art recreational facilities. Therefore, the proposed community center will improve the overall health of the neighborhood.
The author's latest book employs a highly unconventional narrative structure. Thus, the author's latest book will be praised by literary critics.
The new manufacturing process reduces the use of synthetic chemicals by half. Consequently, the new manufacturing process is better for the local environment.
The company's customer service hotline is now available 24 hours a day. As a result, the company's customer retention rate will significantly increase.

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Answer

Pair the community center argument with the health assumption, the author's book argument with the literary critics assumption, the manufacturing process argument with the environment assumption, and the hotline argument with the retention assumption.
In each case, the correct assumption functions as a required bridge that connects the new 'rogue' term in the conclusion back to the evidence provided in the premise. Without these bridges, the conclusions remain completely unsupported.

Step-by-Step Solution

1
Identify the premise and the conclusion in each argument.
Each argument contains a premise (evidence) and a conclusion that introduces a new, unstated concept known as the 'rogue' element.
Finding the new concept in the conclusion is the first step in identifying a missing supporter assumption.
2
Determine the exact logical gap for each argument.
The gaps are: recreational facilities to health, unconventional structure to critic praise, fewer synthetic chemicals to better environment, and 24-hour hotline to higher retention.
A supporter assumption must explicitly connect the evidence in the premise to the new claim in the conclusion.
3
Select the assumption that links the premise concept directly to the conclusion concept.
The matching assumptions form direct 'If Premise, then Conclusion' bridges.
This completes the logical structure, validating each argument.

Key Concept

Bridging Gap (Supporter) Assumptions
Question 265Question →

Analyze each of the following logical arguments. Match each argument to the specific sufficient assumption that, if added to its premises, strictly and logically guarantees the truth of its main conclusion.

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Items

The city council's controversial proposal to ban heavy commercial vehicles in the downtown district will drastically reduce peak-hour traffic congestion. Transportation analysts agree that if traffic congestion is drastically reduced in this manner, overall pedestrian safety will reach historically high levels. Therefore, implementing this proposal ensures that the downtown district will soon experience a significant surge in retail business.
The company's regional branch offices will definitively not be consolidated. After all, the board of directors will approve the highly anticipated corporate merger only if the external auditor's financial forecast predicts significant quarterly growth for the upcoming fiscal year. The recently released financial forecast by the external auditors explicitly does not predict such growth.
Most academic historians who study ancient agrarian societies focus primarily on calculating fluctuating agricultural yields. It is therefore certain that at least some historians who study ancient agrarian societies completely overlook the economic importance of early trade networks. This follows because sociological research demonstrates that some scholars who focus primarily on agricultural yields completely overlook this broader economic importance.
Extensive laboratory testing has demonstrated that reducing oxidative stress generally promotes long-term cellular longevity in mice. Administering a diet rich in synthetic antioxidants effectively reduces oxidative stress in these subjects, but it concurrently inhibits the natural production of critical enzymes regulating basic cellular metabolism. Therefore, feeding laboratory mice a diet rich in synthetic antioxidants will ultimately decrease their overall lifespans.

Matches

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Answer

The public policy argument matches with the safety-to-retail bridge. The corporate merger argument matches with the requirement of board approval for consolidation. The historian argument matches with the universal 'every scholar' claim. The laboratory mice argument matches with the assumption that enzyme inhibition overrides longevity benefits.
The correct matches successfully pair each flawed stimulus with the exact sufficient assumption needed to repair its logic. This involves identifying unstated links between intermediate and main conclusions, tracing formal contrapositives, securing universal quantifier bridges, and establishing definitive dominance in competing causal scenarios.

Step-by-Step Solution

1
Identify the intermediate-to-main gap in the public policy argument regarding traffic.
The argument establishes that banning vehicles leads to pedestrian safety. It concludes this leads to a retail surge. The required gap is 'Pedestrian Safety -> Retail Surge'.
To guarantee the final conclusion, the established intermediate conclusion must be sufficient to trigger the main conclusion.
2
Diagram the conditional logic in the corporate merger argument.
Premises dictate: Approve -> Growth, and ~Growth. Inference: ~Approve. Conclusion: ~Consolidate. The required assumption to bridge the inference and conclusion is ~Approve -> ~Consolidate, or its contrapositive: Consolidate -> Approve.
Sufficient assumptions must formally close the deductive chain from the derived inference directly to the stated conclusion.
3
Evaluate the quantifier overlap in the historical sociology argument.
The premises 'Most A are B' and 'Some B are C' do not guarantee 'Some A are C'. Upgrading the 'Some' to 'All B are C' creates a valid Most + All = Most deduction, ensuring the 'Some' conclusion.
In formal logic, two non-universal quantifiers cannot establish a definitive bridge. A universal 'All' statement is required to guarantee the overlap.
4
Resolve the competing causal vectors in the biological testing argument.
The diet causes both longevity promotion and enzyme inhibition. To definitively conclude a decreased lifespan, the enzyme inhibition must universally cause lifespan reduction and override any longevity benefits.
Without establishing the absolute dominance of the negative causal pathway, the conclusion of an overall decreased lifespan remains merely probable, not logically guaranteed.

Key Concept

Identifying the precise logical gap in an argument's deductive structure and selecting the premise that renders the conclusion 100% valid.
Question 266Question →

In Logical Reasoning, a 'Defender Assumption' is a necessary assumption that protects a causal conclusion by ruling out a specific alternative explanation or vulnerability. Match each causal argument and its corresponding objection (Left) to the precise defender assumption (Right) that the argument MUST make to survive the objection.

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Items

Argument: A pharmaceutical study concludes that Drug X accelerates recovery from illness.
Objection: The study subjects taking Drug X were significantly younger and naturally healthier than the control group.
Argument: A city credits its new policing strategy for a 20% drop in crime.
Objection: A broader demographic aging of the city's population over the same period naturally reduced the population of at-risk youth.
Argument: An economist argues that offering high bonuses causes CEOs to achieve higher corporate profits.
Objection: Companies that are already highly profitable are simply the only ones that can afford to offer high bonuses.
Argument: A biologist concludes that a novel virus caused the rapid extinction of a local predator.
Objection: An unprecedented freeze eliminated the predator's sole food source right before the population collapsed.

Matches

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Answer

The correct mappings uniquely pair each causal vulnerability with the defender assumption that directly negates it. The Drug X argument matches the assumption ruling out physiological resilience; the crime strategy argument matches the assumption ruling out demographic shifts; the corporate bonus argument matches the assumption ruling out pre-existing prosperity; and the predator extinction argument matches the assumption ruling out prey depletion.
Each correct pair links a specific vulnerability in a causal argument to the exact logical negation of that vulnerability. A defender assumption functions by bridging the gap created by an objection; it essentially states 'the alternative explanation raised by the objection is not true.'

Step-by-Step Solution

1
Analyze the pharmaceutical argument and its objection regarding selection bias.
Identify that the argument requires defending against the possibility that pre-existing health differences caused the recovery.
To maintain the conclusion that Drug X caused the recovery, the author must assume that the groups' baseline physiological differences did not independently account for the result.
2
Analyze the policing argument and its objection regarding a simultaneous demographic shift.
Identify that the argument requires defending against a third-variable confounder (an aging populace).
The author must assume the concurrent demographic aging was not the actual driver behind the 20% drop in illicit activity.
3
Analyze the corporate bonus argument and its objection regarding reverse causality.
Identify that the argument requires defending against the possibility that profitability causes high bonuses, rather than vice versa.
The author must assume that the pre-existing financial prosperity of a firm does not dictate its compensation levels, ruling out the reverse causal direction.
4
Analyze the predator extinction argument and its objection regarding an external macro-shock.
Identify that the argument requires defending against an alternate cause (loss of food supply).
The author must assume that the environmental depletion of the prey base was not the true catalyst for the extinction, thereby defending the virus hypothesis.

Key Concept

Ruling Out Alternate Explanations (Defender Assumptions)
Question 267Question →

Match each argumentative scenario with the universal principle that most helps to logically justify its conclusion.

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Items

The new community center will provide a safe space for youth after school. Therefore, the town should fund its construction.
The proposed factory expansion will destroy a critical wetland habitat. Therefore, the environmental committee must veto the expansion.
The new crop variety requires significantly less water than traditional varieties. Therefore, the agricultural board should approve it for commercial farming.
The political candidate has a proven record of increasing voter turnout. Therefore, the political party ought to nominate her.

Matches

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Answer

Each scenario must be matched with the principle that takes its specific premise as a sufficient condition to guarantee its specific conclusion.
In a Principle - Justify question, the correct principle functions as a sufficient premise that connects the specific evidence given to the specific conclusion drawn. By perfectly aligning the 'if' trigger of the principle with the scenario's premise, and the 'then' result of the principle with the scenario's conclusion, the argument becomes logically valid.

Step-by-Step Solution

1
Identify the premise (the factual evidence) and the conclusion (the normative judgment or recommendation) in a given scenario.
Separation of the argument into 'Fact X is true' and 'Therefore, Action Y should happen'.
Justifying an argument requires understanding exactly what evidence is being used to support what claim.
2
Identify the logical gap between the premise and the conclusion.
Recognition that the scenario assumes, without stating, that Fact X is enough to require Action Y.
In Principle - Justify questions, arguments are formally invalid until a broad rule is applied to bridge the gap.
3
Select the principle that explicitly states 'If Fact X, then Action Y'.
The correct principle is matched to the scenario.
A sufficient principle guarantees the conclusion follows logically from the premises provided.

Key Concept

Principle - Justify
Question 268Question →

Match each argument below with the sufficient assumption that logically guarantees its conclusion. Note that one assumption provided is an incorrect trap.

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Items

The proposed highway expansion will increase traffic flow. Thus, the expansion should be approved.
The recently discovered compound contains carbon. Thus, the compound is organic.
The new novel was written by a Nobel laureate. Thus, it will win the book of the year award.
The manufacturing plant uses solar power. Thus, the plant is environmentally friendly.

Matches

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Answer

Highway expansion matches with 'increases traffic flow should be approved'; carbon compound matches with 'contain carbon are organic'; Nobel novel matches with 'written by a Nobel laureate will win'; solar plant matches with 'use solar power are environmentally friendly'.
Each correctly matched assumption follows the formal logic pattern: 'Premise -> Conclusion'. By establishing this universal rule, the fact provided in the premise becomes sufficient to definitively prove the conclusion.

Step-by-Step Solution

1
Analyze each argument to identify its stated premise and its final conclusion.
For example, in the first argument, Premise: 'will increase traffic flow', Conclusion: 'should be approved'.
Finding the structural components of the argument is the first step in identifying the missing logical gap.
2
Determine the required sufficient assumption by linking the premise directly to the conclusion.
The correct format for the assumption is 'If [Premise], then [Conclusion]'. For the first argument, this means 'If it increases traffic flow, it should be approved'.
A sufficient assumption mathematically guarantees the conclusion, completing the deductive bridge.
3
Match each argument with its corresponding 'If Premise, then Conclusion' statement from the available options.
The four correct statements directly link the provided premises to their respective conclusions without reversing the logic.
Reversing the logic (If Conclusion, then Premise) is a common trap and does not guarantee the conclusion.

Key Concept

Sufficient Assumption
Estimated Time:1m 0s
Question 269Question →

Match each flawed argument to the correct description of its logical reasoning error.

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Items

The proposed ban on loud music in the park is supported by Councilman Miller. However, Miller is known for being grumpy and disliking young people. Therefore, the proposed ban is a terrible idea.
A recent study shows that people who drink green tea regularly tend to live longer than those who do not. Clearly, drinking green tea directly extends a person's lifespan.
To bake a perfect loaf of bread, one must use high-quality flour. Susan used the most expensive, high-quality flour available, so her bread is guaranteed to be perfect.
Every individual musician in the city's symphony orchestra is world-renowned and a brilliant soloist. Therefore, the orchestra as a whole must sound brilliant when playing together.

Matches

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Answer

The correct pairings map the Councilman Miller argument to the personal characteristics flaw, the green tea argument to the correlation/causation flaw, the bread argument to the required/guaranteed condition flaw, and the orchestra argument to the parts/whole flaw.
Each argument commits a foundational logical fallacy frequently tested on the exam. The first argument attacks the speaker (Ad Hominem). The second confuses an observed trend with a definitive cause. The third treats an essential ingredient as a guarantee of success (Illegal Reversal). The fourth assumes a group shares the exact traits of its individual members (Composition).

Step-by-Step Solution

1
Analyze each argument to isolate the conclusion and the supporting premises.
Identified the logical leaps: attacking character, confusing correlation with cause, confusing necessary with sufficient, and confusing parts with the whole.
Identifying the disconnect between premise and conclusion is the core task in spotting logical flaws.
2
Review the descriptions of the logical flaws provided in the right-hand list.
Matched the abstract descriptions to the specific flawed patterns identified in Step 1.
LSAT questions require translating specific scenarios into abstract logical rules or flaws.

Key Concept

Flaw in the Reasoning
Question 270Question →

Match each argumentative passage (left) to the abstract description of the specific ad hominem flaw it commits (right).

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Items

Tech CEO Aris Thorne argues that society must adopt strict regulations on smartphone usage to combat declining attention spans. But Thorne himself admits to spending over six hours a day on his own social media platforms. Therefore, his argument for regulation is entirely without merit.
Dr. Vance's comprehensive study concludes that the proposed underground railway is structurally unfeasible and will collapse within a decade. However, we should disregard her findings. She is a major shareholder in the rival above-ground tram company, so she clearly stands to gain financially if the railway project fails.
Professor Lin has published a lengthy critique of my interpretation of the Bronze Age collapse, claiming my timeline ignores crucial geological data. But Lin is famously abrasive, has alienated half his department, and lacks basic professional courtesy. Thus, his critique of my timeline can be safely ignored.
The new curriculum standard emphasizing collaborative problem-solving should be rejected outright. It was championed by the Citizens for Progressive Education, a group whose founding members were recently indicted for embezzling public funds.

Matches

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Answer

The passages map directly to four distinct Ad Hominem sub-categories: the Tech CEO passage matches the behavioral contradiction description (Tu Quoque); the Dr. Vance passage matches the conflict of interest description (Circumstantial Bias); the Professor Lin passage matches the professional decorum description (Abusive); and the curriculum standard passage matches the disreputable organization description (Guilt by Association).
Each passage illustrates a distinct sub-category of the Ad Hominem fallacy. By precisely matching the narrative mechanism of the source attack (hypocrisy, financial bias, bad manners, or criminal association) to its corresponding abstract LSAT description, we accurately identify the specific logical flaw committed in each argument.

Step-by-Step Solution

1
Analyze the Tech CEO argument to identify the precise nature of the source attack.
The argument dismisses a claim because the speaker's own habits (spending six hours on social media) contradict their message (regulating smartphones).
Identifying the specific mechanism of the flaw—hypocrisy—allows us to match it to the description involving 'behavior contradicting tenets'.
2
Analyze the Dr. Vance argument for its core logical misstep.
The argument ignores empirical structural data and attacks the author's financial investments (shares in a rival tram company).
This isolates the 'vested interest' mechanism, separating it from general character attacks, which matches the 'conflict of interest' description.
3
Evaluate the Professor Lin argument's method of rebuttal.
The speaker ignores geological data and instead complains about the professor's abrasiveness and alienation of colleagues.
This confirms a purely abusive, personality-driven attack, perfectly aligning with the description regarding a 'lack of professional decorum'.
4
Examine the curriculum standard argument's reasoning.
A policy is rejected not because of its content, but because of the criminal background of the founders of the group supporting it.
This highlights the 'guilt by association' fallacy, matching the description about 'an organization associated with disreputable activities'.

Key Concept

Ad Hominem (Source Argument) Sub-categories
Question 271Question →

The following arguments each rely on an unstated conditional premise to bridge their evidence to their conclusion. Match each argument with the strictly necessary conditional assumption that logically completes its reasoning.

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Items

The rare alpine orchids require soil with a highly specific mineral composition to survive in the biodome. Since the researchers have successfully synthesized soil that perfectly mimics this composition, it is guaranteed that the orchids will survive.
The city council refuses to raise commercial property taxes this fiscal year. Therefore, the new urban zoning initiative will fail to reduce downtown traffic congestion.
A corporation is subject to federal antitrust scrutiny only when its domestic market share exceeds forty percent. Apex Industries recently acquired its largest competitor, bringing its market share to forty-five percent. Consequently, Apex Industries will now face federal antitrust scrutiny.
An action can be considered morally praiseworthy only if it is performed entirely out of a sense of duty. The altruistic actions performed by our local volunteers are motivated by deep empathy for others. Therefore, the actions of these volunteers are not morally praiseworthy.

Matches

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Answer

Match the orchid argument with the assumption making synthesized soil sufficient for survival; match the traffic argument with the assumption making tax raises necessary for reducing congestion; match the antitrust argument with the assumption making market share sufficient for scrutiny; match the altruism argument with the assumption making empathy mutually exclusive with duty.
Each correct pairing provides the exact formal logical bridge required to make the conclusion of the corresponding argument valid, repairing illegal reversals, linking disparate terms, and forming logically sound contrapositives.

Step-by-Step Solution

1
Analyze the alpine orchids argument.
Identified the argument treats a necessary condition (mineral soil) as sufficient. Matches with the premise establishing that providing the soil guarantees survival.
To prove the conclusion that the orchids will survive, the necessary condition must be formally elevated to a sufficient condition.
2
Analyze the traffic congestion argument.
Identified a missing link between not raising taxes and not reducing congestion. Matches with the premise stating congestion cannot be reduced unless taxes are raised.
The conclusion relies on the contrapositive of the missing premise: If congestion is reduced, taxes are raised. Since taxes are not raised, congestion is not reduced.
3
Analyze the antitrust scrutiny argument.
Identified an illegal reversal involving 'only when'. Matches with the premise stating every corporation with over forty percent market share faces scrutiny.
The argument provides the necessary condition (forty-five percent share) but illicitly concludes the result. The assumption must dictate that the condition is sufficient to guarantee the result.
4
Analyze the moral praiseworthiness argument.
Identified two unconnected sufficient terms (empathy and duty). Matches with the premise stating empathy and duty are mutually exclusive.
To conclude an action is not praiseworthy because it lacks duty (since it was driven by empathy), the author must assume that having empathy means the action was not done entirely out of duty.

Key Concept

Identifying unstated conditional premises and recognizing illegal reversals (confusing necessary and sufficient conditions) in logical arguments.
Question 272Question →

For each logical argument presented, identify the specific piece of additional evidence that provides the strongest logical support for its main conclusion.

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Items

Meteorology: Farms in the western valley that employed a new cloud-seeding technique received 20% more rainfall this season than their historical average. Therefore, the cloud-seeding technique effectively increases precipitation.
Workplace Tech: A software company found that programmers using a newly designed ergonomic keyboard write code 15% faster than those using standard keyboards. Thus, the new keyboard design improves coding speed.
Linguistics: A newly discovered 12th-century text from the isolated Mountain Kingdom contains several words adopted from the Coastal Empire's language. This indicates that the Mountain Kingdom engaged in extensive economic trade with the Coastal Empire.
Zoology: Researchers observed that migratory birds resting in the Northern Wetlands have a significantly higher survival rate during their journey than those resting in the Southern Marshes. Therefore, the Northern Wetlands provide a more nutrient-rich food supply.

Matches

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Answer

The correct pairings align each argument with the evidence that directly resolves its specific logical vulnerability: ruling out alternative weather causes, eliminating selection bias in typists, bridging the conceptual gap to 'trade', and providing a causal mechanism for bird nutrition.
Each correct piece of evidence successfully targets the unstated assumption or vulnerability in its corresponding argument. By either ruling out alternate causes (as in the weather and typing scenarios), bridging a concept shift (in the language scenario), or establishing a clear mechanism (in the bird scenario), the evidence makes each conclusion significantly more likely to be true.

Step-by-Step Solution

1
Analyze the Meteorology argument to identify its underlying assumption.
The argument assumes a causal relationship between cloud-seeding and increased rain. It requires evidence that a natural weather anomaly didn't cause the increase.
Causal claims based on historical comparisons must rule out alternative concurrent causes.
2
Evaluate the Workplace Tech argument's vulnerability.
The argument claims the keyboard causes faster typing, ignoring that fast typists might self-select the new tool. Evidence of random assignment perfectly addresses this.
Eliminating selection bias is a primary way to strengthen observational causal claims.
3
Assess the leap in the Linguistics argument.
The argument leaps from 'borrowed language' to 'economic trade'. Evidence showing the borrowed words are commerce-related bridges this gap.
When a conclusion introduces a new specific concept (trade) not present in the premise (language), a strengthener must link the two.
4
Identify the causal gap in the Zoology argument.
The argument attributes survival to 'nutrient-rich food' without evidence. Confirming the presence of uniquely nutritious, energy-dense plants in the specific area bolsters this.
Providing factual backing for an assumed mechanism strengthens a causal explanation.

Key Concept

Identifying and resolving logical gaps (alternate causes, selection bias, concept shifts) to strengthen arguments.
Question 273Question →

Match each argument below to the piece of new evidence that most directly weakens its conclusion.

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Items

Mayor Smith's popularity must be declining because attendance at her town hall meetings is much lower this year.
City roads are more dangerous than rural roads because a significantly larger total number of car accidents happen in the city.
The new gym will be highly profitable because it is opening right next to a busy organic grocery store.
The herbal tea cures insomnia, as all participants in a recent study reported better sleep after drinking it for a week.

Matches

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Answer

Mayor Smith matches to online broadcasts; City roads match to more miles driven; New gym matches to outdoor preference; Herbal tea matches to prescription medication.
Each correct match directly exploits a specific logical flaw in the argument's reasoning. By introducing alternate explanations, distinguishing totals from rates, attacking unwarranted business assumptions, or introducing confounding variables, the new evidence demonstrates that the original conclusions do not necessarily follow from their premises.

Step-by-Step Solution

1
Analyze the argument regarding Mayor Smith's popularity.
The argument assumes that low physical attendance at meetings definitively proves low popularity.
Identifying the unstated assumption is the first step to finding a weakness.
2
Find the evidence that provides an alternative reason for the low attendance.
The fact that meetings are now broadcast online explains the low physical attendance without requiring a drop in popularity.
An alternate explanation successfully weakens a correlative claim.
3
Analyze the argument regarding city roads and find the structural flaw.
The argument confuses a high total number of accidents with a higher rate of danger. The evidence that city drivers drive millions more miles addresses this total vs. rate flaw.
Understanding the difference between absolute numbers and proportions is crucial to weakening statistical arguments.
4
Analyze the gym and herbal tea arguments to find their respective weakening evidence.
The gym argument is weakened by evidence that the adjacent store's customers dislike indoor gyms. The tea argument is weakened by the introduction of an alternate cause (prescription medication).
Each piece of correct evidence successfully severs the assumed logical link between the given premises and the final conclusions.

Key Concept

Evaluating Arguments: Weakening
Question 274Question →

Match each flawed argument scenario on the left with the abstract description of its specific sampling or survey flaw on the right.

Click a left item, then click its matching right item

Items

A news anchor concludes that the city overwhelmingly opposes a new tax based on emails sent by viewers during a broadcast.
An author asserts that a specific business strategy ensures long-term wealth by analyzing the habits of fifty currently successful billionaires.
A researcher determines that a national candidate is unpopular with youth after surveying students at a single, politically homogeneous private college.
A consumer claims a new vehicle model has defective brakes because three recent buyers reported brake failures within a week of purchase.

Matches

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Answer

The viewer emails scenario maps to individuals who actively opted to express opinions. The billionaire scenario maps to entities that have already survived a selection process. The private college scenario maps to a remarkably narrow and unrepresentative demographic subset. The brake failure scenario maps to an inadequately small number of isolated anecdotes.
Each flawed argument neatly maps to a distinct sampling error. The email survey fails due to self-selection (voluntary response bias). The billionaire study is flawed because it ignores those who failed (survivorship bias). The college poll surveys an insular group to make a broad claim (unrepresentative demographic subset). The brake failure claim relies on too few data points (small sample size).

Step-by-Step Solution

1
Analyze the news anchor scenario.
Identified that the sample relies entirely on people who actively chose to send emails.
This matches the abstract description of voluntary opt-in response bias.
2
Analyze the billionaire scenario.
Identified that the sample only includes people who are already financially successful.
This matches the abstract description of survivorship bias, which ignores failures.
3
Analyze the college student scenario.
Identified that the sample represents a very specific, homogeneous group rather than the diverse national youth population.
This matches the abstract description of surveying a narrow, unrepresentative demographic subset.
4
Analyze the vehicle buyer scenario.
Identified that the sweeping conclusion is based on merely three incidents.
This matches the abstract description of generalizing from an inadequately small number of anecdotes.

Key Concept

Identifying the specific mechanism by which a sample fails to accurately represent the target population in inductive reasoning.
Estimated Time:1m 30s
Question 275Question →

An urban planner argues: 'Last year, our city installed a new smart traffic light network at ten major intersections. Over the past twelve months, traffic accidents at these specific intersections decreased by 30%. Therefore, the new smart traffic lights directly caused this significant reduction in accidents.'

Match each potential alternate explanation (objection) on the left with the specific defender assumption on the right that the urban planner must rely on to neutralize that threat to the causal claim.

Click a left item, then click its matching right item

Items

A new highway bypass recently opened, diverting a substantial amount of vehicle traffic away from the targeted intersections.
The city simultaneously doubled police patrols at the targeted intersections to monitor the implementation of the new system.
The targeted intersections were chosen solely because they experienced an anomalous, statistically rare spike in accidents the prior year.
The year prior to the installation featured record-breaking ice storms, while the past twelve months had unusually clear weather.

Matches

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Answer

Match the highway bypass to the assumption about car volume; the police patrols to the assumption about law enforcement; the anomalous spike to the assumption about historical baselines; and the weather changes to the assumption about mild climate.
In causal reasoning, a defender assumption protects the argument by explicitly ruling out an alternative explanation for the evidence. By matching each specific threat (alternate cause) with the assumption that negates it, we logically insulate the author's claim that the smart lights were the true cause.

Step-by-Step Solution

1
Analyze the causal argument in the stem.
The argument concludes that A (smart lights) caused B (reduced accidents) based on the premise that B followed A.
Identifying the cause and effect is required to understand what alternate explanations threaten the conclusion.
2
Understand the function of a defender assumption.
A defender assumption eliminates a specific alternate cause or confounding variable that could explain the observed effect.
This establishes the rule for matching: the correct assumption must directly negate the specific alternate explanation proposed in the left column.
3
Evaluate each alternate explanation and pair it with its logical negation.
Highway bypass (volume drop) pairs with the assumption of no volume drop. Police pairs with no law enforcement effect. Statistical anomaly pairs with no reversion to baseline. Weather pairs with no climate effect.
This guarantees that if the assumption is true, the specific threat to the author's causal claim is successfully eliminated.

Key Concept

Defender Assumptions (Ruling out alternative causes)
Question 276Question →

Below are four distinct arguments that conclude a causal relationship based on observed evidence. For each argument, identify the specific logical gap it leaves open by matching it to the core assumption necessary to bridge that gap.

Click a left item, then click its matching right item

Items

Data collected from smartphone users reveals a strong positive correlation between the daily use of dietary tracking apps and clinical anxiety. Psychologists hypothesize that the constant pressure to log meals directly generates psychological distress.
A manufacturing plant saw its total weekly output surge by 20 percent in the months following a major upgrade to its ventilation system. Management credits the superior air quality for this dramatic boost in worker productivity.
Since a corporation instituted a zero-tolerance penalty for workplace incivility, the total volume of complaints filed with human resources has fallen by half. Executives assert that the new rule has effectively fostered a more polite workforce.
Urban areas boasting a high concentration of artisanal coffee shops also exhibit a much higher rate of software patents registered per capita. Urban planners deduce that the culture of frequenting these shops stimulates technological innovation.

Matches

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Answer

Smartphone data pairs with Reversed causality; Manufacturing plant pairs with Alternative simultaneous intervention; Corporation policy pairs with Reluctance to come forward; Urban areas pairs with Overarching demographic variable.
Each argument represents a distinct manifestation of causal reasoning on the LSAT, requiring a specific assumption type to be valid. The smartphone argument assumes causality isn't reversed. The plant argument assumes no alternate, simultaneous event occurred. The corporate policy argument assumes the reporting metric reliably reflects reality. The urban area argument assumes a common third cause isn't responsible for both trends.

Step-by-Step Solution

1
Analyze the 'Smartphone data' argument.
The argument observes a correlation between tracking apps and anxiety, concluding apps cause anxiety. It requires the assumption that anxiety does not cause people to use tracking apps.
This is a classic reverse causation vulnerability.
2
Analyze the 'Manufacturing plant' argument.
The argument observes a sequential change (ventilation upgrade followed by productivity boost) and concludes causation. It requires the assumption that no other simultaneous change caused the boost.
Arguments based on sequential events are highly vulnerable to alternate, simultaneous causes.
3
Analyze the 'Corporation policy' argument.
The argument equates a drop in reported complaints with a drop in actual incivility. It assumes the reporting metric is a reliable indicator of reality.
Policies with severe penalties often suppress the reporting of an issue rather than eliminating the underlying behavior.
4
Analyze the 'Urban areas' argument.
The argument correlates coffee shops with patents, assuming one causes the other. It assumes a third variable (like a booming tech sector) isn't causing both.
Correlations between two distinct cultural or economic markers often stem from a shared third cause.

Key Concept

Identifying the specific type of unstated assumption required to validate a causal argument, such as ruling out reverse causation, alternate causes, data unreliability, or common third variables.
Question 277Question →

Review the following short arguments, each of which contains a reasoning flaw related to time shifts. Match each argument to the description that most accurately identifies its specific temporal fallacy.

Click a left item, then click its matching right item

Items

NovaCorp has maintained peak profitability for a decade by focusing exclusively on physical retail stores. Therefore, maintaining this exclusive focus guarantees NovaCorp's continued profitability over the next decade.
Records dating back three centuries show the regional aquifer has never dropped below a reserve of 40%. Consequently, the new agricultural irrigation initiative cannot possibly deplete the aquifer.
Since the introduction of electric vehicles, the percentage of citizens using public transit has decreased slightly each year. It is clear that public transit systems will eventually lose all their ridership.
When the city suspended downtown parking fees in 1995, local retail revenue soared for six months. Thus, suspending downtown parking fees next month will certainly produce a comparable retail boom.

Matches

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Answer

NovaCorp matches the assumption of persisting business conditions; the aquifer matches the assumption that historical absence proves future impossibility; the transit argument matches the unwarranted projection of a trend to zero; the parking fee argument matches the assumption of static background circumstances for a past intervention.
Each argument inappropriately leverages past or present data to make an unwarranted claim about the future. By identifying the specific nature of the premise (a trend, a historical absence, a past success, a discrete past policy) and the nature of the conclusion (absolute zero, impossibility, guaranteed future success, identical policy outcome), each argument can be mapped to its precise abstract flaw description.

Step-by-Step Solution

1
Analyze the NovaCorp argument to isolate the time shift.
It infers future guaranteed success from the past success of an ongoing strategy.
This corresponds to taking for granted that a strategy succeeding under past conditions will remain optimal.
2
Analyze the regional aquifer argument.
It infers future physical impossibility of depletion based entirely on a historical lack of occurrence.
This corresponds to treating the historical absence of an extreme event as definitive proof it cannot happen.
3
Analyze the public transit argument.
It extrapolates an ongoing, slight annual decline to a conclusion of absolute zero.
This corresponds to projecting a directional trend indefinitely without considering a plateau.
4
Analyze the downtown parking fees argument.
It infers that repeating a discrete past action from 1995 will yield the exact same result today.
This corresponds to treating a historical correlation as a causal guarantee for a future intervention.

Key Concept

Time Shift Flaws (Past vs. Future)
Question 278Question →

Analyze each of the following logical arguments regarding a proposed city library project. Match each argument with the sufficient assumption that logically guarantees its conclusion.

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Items

The new library will be constructed only if the federal grant is approved. The federal grant has just been approved. Thus, construction on the new library will undoubtedly begin.
If the city council approves the rezoning, the new library will be constructed. The mayor has expressed her full support for the project. Therefore, the new library will be constructed.
Constructing the new library will revitalize the downtown area. As a direct result, the city's overall tax revenue will experience a significant increase.
Unless the old community center is demolished, the new library cannot be constructed. The historical society has successfully blocked the demolition. Therefore, the federal grant will surely be revoked.

Matches

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Answer

Argument 1 matches with 'Approval of the federal grant is all that is required...'; Argument 2 matches with 'The mayor's endorsement of the project guarantees...'; Argument 3 matches with 'Any revitalization of the downtown area inevitably leads...'; Argument 4 matches with 'Failing to construct the new library guarantees...'
Each argument contains a specific logical gap that must be closed for its conclusion to be strictly justified. The correct pairs provide the exact conditional bridge (A -> B) needed to connect the disjointed premises to their respective conclusions.

Step-by-Step Solution

1
Analyze the first argument for its logical gap.
Premise: Construction requires Grant Approval. Fact: Grant Approved. Conclusion: Construction. Gap: Assumes Grant Approval guarantees Construction.
Identifying the formal logic structure reveals an illegal reversal, requiring an assumption that makes the necessary condition sufficient.
2
Analyze the second argument for its logical gap.
Premise: Rezoning guarantees Construction. Fact: Mayor Supports. Conclusion: Construction. Gap: Mayor Supports must guarantee Rezoning.
The conclusion relies on a conditional statement being triggered, requiring a link between the new evidence (mayor's support) and the trigger (rezoning).
3
Analyze the third argument for its logical gap.
Premise: Construction guarantees Revitalization. Conclusion: Construction guarantees Tax Increase. Gap: Revitalization must guarantee Tax Increase.
The conclusion introduces 'tax revenue', a new concept not found in the premises, which must be logically linked to the intermediate result.
4
Analyze the fourth argument for its logical gap.
Premise: Construction requires Demolition. Fact: No Demolition. Intermediate: No Construction. Conclusion: Grant Revoked. Gap: No Construction must guarantee Grant Revoked.
The contrapositive establishes the library won't be built. A bridge is needed to connect this established fact to the totally new consequence (grant revoked).

Key Concept

Identifying Sufficient Assumptions
Question 279Question →

Match each paradoxical situation with the statement that best resolves the apparent discrepancy.

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Items

A city added lanes to its busiest highway to ease congestion, but traffic jams on that highway immediately worsened.
A luxury perfume brand cut its prices in half, but the number of bottles sold actually decreased.
A farm switched to a cheaper type of cattle feed to save money, yet its total daily feeding costs increased.

Matches

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Answer

The highway expansion paradox is resolved by the shift of commuters from trains to cars. The luxury perfume paradox is resolved by the loss of the product's exclusive image. The cheaper feed paradox is resolved by the need to consume significantly more feed.
Each correct match provides a piece of new information that actively bridges the gap between an action and its surprising result. For the highway, it introduces a behavioral shift. For the perfume, it introduces the concept of prestige pricing. For the farm, it introduces the relationship between nutritional density and required volume.

Step-by-Step Solution

1
Analyze the highway paradox.
The paradox is that increasing road space worsened traffic. The matching resolution shows how more space led to even more cars.
Resolving a paradox requires finding a new fact that makes both original facts compatible.
2
Analyze the luxury perfume paradox.
The paradox is that lowering prices reduced sales. The matching resolution shows that the price cut removed the primary reason people bought the product.
We must explain why a normal economic principle failed in this specific scenario.
3
Analyze the farm feed paradox.
The paradox is that cheaper feed raised total costs. The matching resolution shows that the farm had to buy vastly more of the new feed.
Total cost depends on both price per unit and quantity used; changing one can offset the other.

Key Concept

Explaining Surprising Outcomes
Question 280Question →

Analyze the following four arguments, each of which draws a flawed conclusion about the present or future based on past conditions. Match each argument to the statement that best diagnoses its specific time-shift fallacy.

Click a left item, then click its matching right item

Items

City Planner: This intersection has operated without a single major collision since it was constructed fifty years ago. Therefore, we do not need to install traffic lights even with the opening of the new shopping complex on the adjacent lot.
Promoter: The Crimson Phantoms' upcoming reunion tour will undoubtedly sell out every stadium. After all, during their prime in the late 1980s, every single concert they played was sold out within minutes.
Financial Advisor: Invest in StartUp-X immediately. Their valuation has grown by exactly 20 percent each month for the last twelve months, so you can expect a 20 percent return on your investment next month.
Inspector: There is no need to test the drinking water at the old municipal building for lead contamination this year. The pipes were comprehensively evaluated a decade ago and declared completely free of lead.

Matches

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Answer

City Planner matches the failure to consider new variables; Promoter matches the failure to consider shifting public tastes; Financial Advisor matches the unwarranted projection of a historical trend; Inspector matches the presumption of a static physical state.
Each argument contains a distinct variation of the time shift flaw. The City Planner ignores new environmental variables (the mall). The Promoter ignores changing cultural tastes over time. The Financial Advisor unjustifiably extrapolates a short-term trend. The Inspector assumes a physical state is immune to degradation over a decade. Matching these specific logical errors to their precise descriptions correctly identifies the flaws.

Step-by-Step Solution

1
Analyze the City Planner's argument for its specific temporal assumption.
The argument uses a past record of safety to predict future safety but explicitly ignores a newly introduced factor (the shopping complex).
Identifying the specific mechanism of the flaw—ignoring a new variable that disrupts the historical pattern—is required to find the matching description.
2
Analyze the Promoter's argument for its specific temporal assumption.
The argument assumes that a band's massive success in the 1980s guarantees success today.
Recognizing the failure to account for changing tastes over decades pinpoints the flaw of assuming static popularity.
3
Analyze the Financial Advisor's argument for its specific temporal assumption.
The argument expects a past mathematical trend (20 percent monthly growth) to continue automatically into the future.
Recognizing the unwarranted extrapolation of a numerical trend allows for matching with the correct diagnosis regarding historical trends.
4
Analyze the Inspector's argument for its specific temporal assumption.
The argument assumes that a physical condition (lead-free pipes) tested in the past remains static a decade later.
Identifying the assumption of a permanent physical state helps select the description regarding degradation or alteration over time.

Key Concept

Time Shift Flaws often occur when an author assumes that conditions present in the past will remain unchanged in the present or future, failing to account for new variables, changing trends, or the natural degradation of physical states over time.
Estimated Time:1m 30s
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