Examkin

Parallel Reasoning

98 questions

All types98Multiple choice55Multiple select4True / False5Matching34
Question 1Question →

Evaluate the flawed logic presented in the arguments below. Connect each specific argument to the generalized description of its underlying error.

Click a left item, then click its matching right item

Items

Whenever a software development team relies heavily on automated testing, they produce highly stable applications. The new mobile app from Zenith Tech is highly stable, which proves that Zenith Tech's developers relied heavily on automated testing.
Historical data indicates that civilizations located near major river systems typically develop complex agricultural economies. It is therefore evident that settling near a major river system is what directly causes a civilization to develop a complex agricultural economy.
Any student who receives personal tutoring in mathematics will pass the final exam. Unfortunately, David did not receive any personal tutoring in mathematics this semester. We can conclude that David will fail the final exam.
Every single brick used in the construction of the historical monument is incredibly light and easy to carry. Therefore, the historical monument as a whole must be incredibly light and easy to carry.

Matches

Show answer & explanation

Answer

The arguments match their abstract flaws as follows: The software testing argument matches treating a sufficient condition as necessary. The river civilization argument matches inferring causation from association. The math tutoring argument matches concluding a result will not occur because a sufficient condition is absent. The brick monument argument matches assuming a characteristic of parts applies to the whole.
Each argument contains a distinct, identifiable logical error. The software argument affirms the consequent (illegal reversal). The river argument confuses correlation with causation. The tutoring argument denies the antecedent (illegal negation). The brick argument commits the fallacy of composition (part-to-whole). The correct pairings accurately align each argument's specific error with its generalized logical description.

Step-by-Step Solution

1
Analyze the software development argument.
Identified a conditional reasoning flaw where the premise 'A implies B' is incorrectly reversed to 'B implies A' (affirming the consequent).
To match the argument with the generalized description of treating a sufficient condition as necessary.
2
Examine the river systems argument.
Identified a causal reasoning flaw where a correlation between rivers and agriculture is incorrectly treated as a definitive cause-and-effect relationship.
To find the abstract description describing causal inference drawn from mere association.
3
Analyze the mathematics tutoring argument.
Identified a conditional reasoning flaw where the premise 'A implies B' is incorrectly manipulated to 'Not A implies Not B' (denying the antecedent).
To match the argument with the description of concluding a result won't occur because a sufficient condition is absent.
4
Evaluate the historical monument argument.
Identified a composition flaw where the physical properties of a building's materials are improperly attributed to the building as a whole.
To find the abstract description of assuming parts apply unconditionally to the whole.

Key Concept

Parallel Flaw
Question 2Question →

The annual spring festival will definitely not be held in the town square this year. We know this because the festival is held in the square whenever the municipal budget runs a surplus and the mayor's office approves the permit. However, the municipal budget is not running a surplus this year.

Which one of the following arguments exhibits a flawed pattern of reasoning most similar to that exhibited by the argument above?

Show answer & explanation

Answer: Whenever the beta testing phase finds no critical bugs and the marketing campaign is finalized, the new software update is released on schedule. Yet, because the marketing campaign has not been finalized, the software update will not be released on schedule.

Answer

The argument concluding that the software update will not be released on schedule because the marketing campaign has not been finalized.
The stimulus commits an illegal negation by treating a compound sufficient condition as a necessary one. It establishes that two things together (budget surplus AND permit approval) guarantee an outcome. It then points out that one of those things didn't happen, and concludes the outcome won't happen. The correct answer has the exact same structure: it establishes that two things (no bugs AND marketing finalized) guarantee an outcome (released on schedule), notes that one didn't happen (marketing not finalized), and relies on flawed logic to conclude the outcome will not happen.

Step-by-Step Solution

1
Analyze the stimulus to identify the conclusion and premises.
Conclusion: The festival will not be held in the square. Premise 1: If budget runs a surplus AND permit is approved, then the festival is held in the square. Premise 2: The budget is not running a surplus.
Deconstructing the argument into formal logic is necessary to identify the exact structural flaw before examining the choices.
2
Identify the logical flaw in the stimulus.
The flaw is an illegal negation of a compound sufficient condition. The argument assumes that because one required part of the sufficient condition failed, the necessary result cannot occur, ignoring that there could be alternate ways to trigger the result.
Knowing the precise flaw prevents being distracted by arguments that are flawed but structurally different.
3
Evaluate the answer choices to find the matching abstract structure.
The software update argument matches: Premise 1 is (No bugs AND marketing finalized) -> released on schedule. Premise 2 is ~Marketing finalized. Conclusion is ~Released on schedule.
The correct answer in a Parallel Flaw question must match both the specific logical error and the structural components of the original argument.

Key Concept

Parallel Flaw - Illegal Negation of a Compound Condition
Question 3Question →

A recent survey of corporate executives found that those who take frequent vacations are significantly more likely to receive promotions than those who take few vacations. The researchers concluded that taking time off from work reduces burnout, which in turn leads to career advancement.

The flawed reasoning in the argument above is most similar to that in which one of the following?

Show answer & explanation

Answer: Data shows that cities with an abundance of public parks tend to have higher average property values than cities with fewer parks. This demonstrates that building public spaces fosters community engagement, which consequently drives up real estate prices.

Answer

The argument concluding that building public spaces fosters community engagement, which consequently drives up real estate prices.
The correct answer perfectly mirrors the logical structure of the stimulus. Both arguments begin with a premise establishing a statistical correlation between two phenomena (vacations and promotions; parks and property values). Both then conclude with a definitive causal relationship, notably introducing a brand-new intermediate mechanism in the conclusion to explain the causality (reduced burnout; community engagement) that was entirely absent from the premises.

Step-by-Step Solution

1
Analyze the structural components of the stimulus argument.
Premise: Correlation between X (vacations) and Y (promotions). Conclusion: X causes an unstated intermediate factor Z (reduced burnout), which in turn causes Y.
Identifying the exact premise-to-conclusion logical pathway is required to find a structural match in Parallel Reasoning questions.
2
Identify the logical flaw and the specific causal features.
The argument makes a definitive causal claim based entirely on a statistical correlation, and uniquely introduces a novel intermediate explanatory mechanism in the conclusion.
The correct answer must replicate this exact causal jump, matching the direction of causality and the introduction of a middle step.
3
Evaluate the options against the stimulus structure.
The option concerning public parks matches perfectly: it moves from a correlation (parks and property values) to a definitive causal chain involving a new intermediate mechanism (community engagement).
Parallel arguments must match the causal direction, conclusion certainty, and structural quirks of the original argument.

Key Concept

Parallel Causal Reasoning
Question 4Question →

We can conclude that the majority of modernist civic centers designed in the mid-twentieth century suffer from severe thermal regulation issues. After all, most of these civic centers incorporate extensive raw concrete facades, and it is well documented that most structures incorporating extensive raw concrete facades suffer from such thermal issues.

Which of the following arguments contains a flawed pattern of reasoning most similar to the one exhibited in the argument above?

Show answer & explanation

Answer: Most hybrid sedans currently on the market are equipped with regenerative braking systems. Therefore, most hybrid sedans require specialized mechanic certification to service, since the majority of vehicles equipped with regenerative braking systems require such certification.

Answer

The argument about hybrid sedans and regenerative braking systems.
The correct answer accurately replicates the 'chaining mosts' quantifier flaw seen in the stimulus. In the stimulus, the argument assumes that because most civic centers (A) have concrete facades (B), and most structures with concrete facades (B) have thermal issues (C), then most civic centers (A) must have thermal issues (C). The correct answer uses the exact same flawed reasoning: Most hybrid sedans (A) have regenerative braking (B), and most vehicles with regenerative braking (B) need certification (C), therefore most hybrid sedans (A) need certification (C). The order of the sentences is slightly varied, but the logical dependencies are identical.

Step-by-Step Solution

1
Abstract the logical structure of the stimulus.
Conclusion: Most A are C. Premise 1: Most A are B. Premise 2: Most B are C.
Identifying the formal structure allows for an objective comparison of reasoning patterns, independent of the subject matter.
2
Identify the specific logical flaw in the abstracted structure.
The flaw is Quantifier Overreach. Just because Most A are B, and Most B are C, it does not guarantee that the A's and C's overlap. (e.g., Most dogs are pets. Most pets are cats. Therefore, most dogs are cats. - Invalid).
Understanding why the stimulus is flawed ensures the correct answer choice is selected for the right structural reason.
3
Evaluate the answer choices to find the exact structural match.
The correct option abstract is: Premise 1: Most A are B. Conclusion: Most A are C. Premise 2: Most B are C. Despite a different ordering of premises and conclusion, the logical linkage and the flaw perfectly match the stimulus.
Parallel reasoning questions often vary the presentation order to test true structural understanding rather than superficial reading.

Key Concept

Parallel Flaw - Quantifier Overreach
Question 5Question →

For a symphony orchestra to be world-class, it must either receive substantial government subsidies or possess an immense private endowment. Any orchestra operating in a nation with a strictly privatized arts sector receives no government subsidies. The Philharmonia Orchestra operates in a nation with a strictly privatized arts sector, yet it lacks an immense private endowment. Therefore, the Philharmonia Orchestra is not a world-class symphony orchestra.

Which of the following arguments is most similar in its logical structure to the argument above?

Show answer & explanation

Answer: To receive a coveted culinary star, a restaurant must either employ a formally trained head chef or exclusively use hyper-local ingredients. Any restaurant located within a major international airport is unable to employ a formally trained head chef. The Brasserie operates within a major international airport and does not use hyper-local ingredients. Thus, The Brasserie will not receive a coveted culinary star.

Answer

The argument about a restaurant receiving a coveted culinary star perfectly mirrors the logical structure of the stimulus.
The correct answer accurately mirrors the complex valid deductive structure of the stimulus: it outlines a goal that requires at least one of two conditions (A -> B or C), provides a rule that eliminates the first condition for a specific category (D -> ~B), places a specific entity in that category while also stating it lacks the second condition (Entity E is D and ~C), and validly concludes the entity cannot achieve the goal (Therefore, ~A).

Step-by-Step Solution

1
Analyze the formal logic of the stimulus.
Condition 1: World-Class (WC) -> Government Subsidies (GS) OR Private Endowment (PE). Condition 2: Privatized Arts (PA) -> NOT GS. Premise: Philharmonia is PA AND NOT PE. Conclusion: Philharmonia is NOT WC.
Identifying the abstract architecture of the argument is essential before evaluating the answer choices.
2
Summarize the overarching structural pattern.
To achieve A, one must have B or C. All D lack B. Entity E is D, and lacks C. Therefore, E cannot achieve A.
Creating a generalized template allows for rapid matching without being distracted by subject matter.
3
Evaluate the answer choices against the template.
The correct restaurant argument maps flawlessly: Michelin Star (A) -> Formal Chef (B) OR Hyper-local (C). Airport (D) -> NOT Formal Chef (B). Brasserie (E) is Airport (D) AND NOT Hyper-local (C). Therefore, Brasserie is NOT Michelin Star (A).
Matching each variable verifies that the logical structure, quantifier strength, and conclusion direction are completely parallel.

Key Concept

Parallel Valid Structure (Disjunctive Necessary Conditions and Modus Tollens)
Estimated Time:2m 30s
Question 6Question →

A municipal government's achievement of a significantly reduced budget deficit is strictly contingent upon the implementation of comprehensive tax reforms. The implementation of such reforms, in turn, invariably precipitates widespread public dissatisfaction in the short term. Consequently, any municipality currently experiencing widespread short-term public dissatisfaction must have succeeded in significantly reducing its budget deficit.

Which one of the following arguments contains a flawed pattern of reasoning most similar to the one in the argument above?

Show answer & explanation

Answer: Consistently attending the weekly seminar invariably guarantees that a student will receive a glowing letter of recommendation from the department chair. Furthermore, a student's mastery of the advanced physics curriculum is strictly contingent upon their consistent attendance at this seminar. It follows that any student in possession of such a recommendation letter must have mastered the advanced physics curriculum.

Answer

The correct argument is the one concluding that any student possessing a recommendation letter must have mastered the advanced physics curriculum.
The stimulus exhibits an Illegal Reversal of a transitive conditional chain. It establishes that reducing a deficit (A) requires tax reforms (B), and tax reforms (B) always lead to dissatisfaction (C). The valid inference is A -> C. However, the stimulus concludes that experiencing dissatisfaction (C) proves the deficit was reduced (A). The correct answer structurally replicates this exact flaw: it establishes that mastery (A) requires attendance (B), and attendance (B) guarantees a letter (C). It then incorrectly concludes that having a letter (C) guarantees mastery (A). Although the premises in the correct option are presented in reverse order compared to the stimulus, the underlying flawed logical structure (A -> B, B -> C, therefore C -> A) is identical.

Step-by-Step Solution

1
Analyze the stimulus structure
The stimulus creates a conditional chain: Reduced Deficit -> Tax Reforms, and Tax Reforms -> Public Dissatisfaction. Therefore, the valid chain is: Reduced Deficit -> Public Dissatisfaction.
Mapping the exact conditional relationships between the premises is required before diagnosing the flaw.
2
Identify the logical flaw in the stimulus
The stimulus concludes that Public Dissatisfaction -> Reduced Deficit. This is an Illegal Reversal of the entire transitive chain.
You must pinpoint the exact nature of the error in abstract terms to find its structural parallel.
3
Evaluate the options for a matching structure
Look for an option that presents a chain (A -> B and B -> C) but concludes C -> A. The correct option regarding the physics curriculum has this exact structural error.
Parallel reasoning requires matching the abstract logical error, regardless of the subject matter or the order in which the premises are presented.

Key Concept

Parallel Flaw - Transitive Illegal Reversal
Question 7Question →

Assess the following four excerpts drawn from various specialized fields. Match each argument with the abstract description that most precisely identifies its logical vulnerability.

Click a left item, then click its matching right item

Items

In modern architectural design, every individual load-bearing column used in the museum's new wing has been subjected to rigorous stress tests to ensure maximum tensile strength. From this, the chief architect has deduced that the entire architectural framework of the wing possesses maximum tensile strength.
Preserving the delicate ecological balance of the wetland reserve during periods of severe drought demands the systematic introduction of drought-resistant flora. The conservation authority has comprehensively introduced such flora throughout the reserve this season; hence, the wetland's ecological balance will certainly be preserved.
An extensive epidemiological study found that individuals who consume high amounts of synthetic antioxidants exhibit a notably lower incidence of degenerative joint diseases than those who do not. This conclusively demonstrates that the ingestion of synthetic antioxidants prevents the deterioration of joint cartilage.
The municipal zoning code explicitly states that exemptions for commercial building height restrictions are granted only to structures serving a 'public interest'. The proposed luxury high-rise will generate massive public interest due to its controversial design and celebrity architect. Consequently, the high-rise qualifies for the height restriction exemption.

Matches

Show answer & explanation

Answer

The architectural argument exhibits a Composition flaw; the wetland argument exhibits a Necessary vs. Sufficient flaw; the epidemiological argument exhibits a Correlation vs. Causation flaw; and the zoning argument exhibits an Equivocation flaw.
Each excerpt perfectly maps to a foundational logical fallacy: generalizing from parts to a whole (Composition), treating a requirement as a guarantee (Necessary vs. Sufficient), inferring causation strictly from correlation, and shifting the definition of a key term mid-argument (Equivocation).

Step-by-Step Solution

1
Analyze the architectural argument's structural shift.
The premise addresses individual columns, but the conclusion addresses the entire framework.
Identifying the shift from component parts to the entire integrated system isolates the Part-to-Whole (Composition) logical error.
2
Analyze the conditional logic in the wetland argument.
The argument states introducing flora is required ('demands') but concludes it guarantees the outcome ('will certainly be preserved').
Recognizing the conflation of a requirement with a guarantee pinpoints the Confusion of Necessary and Sufficient conditions.
3
Evaluate the evidence-to-conclusion leap in the epidemiological argument.
The evidence is a statistical association, yet the conclusion asserts a direct preventative mechanism.
Noting the transition from correlational data to a definitive causal claim highlights the Correlation vs. Causation fallacy.
4
Examine the usage of key terminology in the zoning argument.
The phrase 'public interest' shifts from meaning civic utility in the premise to meaning widespread curiosity in the conclusion.
Spotting the semantic manipulation of a single phrase reveals the Equivocation fallacy.

Key Concept

Identifying and abstracting formal logical flaws (Parallel Flaw)
Question 8Question →

A recent study found that cities with higher per capita spending on public parks have significantly lower rates of stress-related illnesses. The mayor argues that building more parks will therefore improve public health. However, this reasoning is flawed. The study also revealed that cities with higher park spending possess higher average incomes, and higher income allows for better access to preventive healthcare. Therefore, the lower rates of stress-related illnesses are entirely due to higher incomes, and public parks provide no actual health benefits.

Which one of the following arguments exhibits a flawed pattern of reasoning most similar to that exhibited in the argument above?

Show answer & explanation

Answer: Data shows that people who drink green tea daily have a lower risk of heart disease. Nutritionists conclude that green tea prevents heart disease. Yet, daily green tea drinkers also tend to exercise regularly, which is known to strengthen the heart. Consequently, the reduced risk of heart disease is solely the result of regular exercise, and green tea provides no cardiovascular benefit.

Answer

The argument about green tea and exercise perfectly parallels the flawed causal reasoning in the stimulus.
The correct answer accurately mirrors the specific flawed causal structure of the stimulus. It presents an initial correlation (green tea and lower heart disease risk), states a proposed causal claim, introduces a third variable (exercise) that is correlated with the first and causes the outcome, and then commits the exact same logical fallacy: assuming that this third variable is the EXCLUSIVE cause, thereby concluding that the original proposed cause has absolutely no effect.

Step-by-Step Solution

1
Analyze the causal structure of the stimulus.
Structure: A (parks) is correlated with B (better health). Claim: A causes B. Counter-evidence: A is correlated with C (income), and C causes B.
Understanding the exact causal relationships and premises is required to find a parallel structure.
2
Identify the logical flaw in the stimulus.
Flaw: The author assumes that because C is a cause of B, C must be the EXCLUSIVE cause of B, concluding that A has absolutely no effect.
Parallel reasoning questions require matching both the logical structure and the specific reasoning error.
3
Evaluate the options for a matching structure and matching flaw.
The correct option mirrors the structure: A (green tea) correlated with B (heart health). Claim: A causes B. Counter: A is correlated with C (exercise), and C causes B. Flawed conclusion: C is the sole cause, A has no effect.
This is the only option that matches the specific 'alternative exclusive cause' fallacy with the same degree of absolute certainty.

Key Concept

Parallel Causal Reasoning
Question 9Question →

Analyze the natural language arguments below. Match each argument to its corresponding formal symbolic conditional skeleton.

Click a left item, then click its matching right item

Items

If a species is considered invasive, it threatens local biodiversity. Any species that threatens local biodiversity is subject to removal. Therefore, if a species is considered invasive, it is subject to removal.
An applicant will be approved for the advanced grant only if they have published peer-reviewed research. Dr. Aris has not published peer-reviewed research. Consequently, Dr. Aris will not be approved for the advanced grant.
A robust marketing campaign is required for a startup to achieve profitability. The startup TechNova recently launched a robust marketing campaign. It follows that TechNova will achieve profitability.
Provided that a contract includes a non-compete clause, it is legally binding. The new employment contract does not include a non-compete clause. Thus, the new employment contract is not legally binding.

Matches

Show answer & explanation

Answer

Argument 1 matches the Valid Chain; Argument 2 matches the Valid Contrapositive; Argument 3 matches the Flawed Reversal; Argument 4 matches the Flawed Negation.
Each argument translates to a specific symbolic structure based on its conditional indicators. By identifying whether a condition is sufficient ('if', 'any', 'provided that') or necessary ('only if', 'is required for'), we can diagram the argument properly and classify it as a valid deduction or a formal flaw.

Step-by-Step Solution

1
Diagram Argument 1.
Invasive (X) → Threatens (Y); Threatens (Y) → Removal (Z). Conclusion: Invasive (X) → Removal (Z).
The indicators 'If' and 'Any' both introduce sufficient conditions, creating a Valid Transitive Chain.
2
Diagram Argument 2.
Approved (X) → Published (Y); ~Published (~Y). Conclusion: ~Approved (~X).
The indicator 'only if' introduces a necessary condition. Denying it yields a Valid Contrapositive.
3
Diagram Argument 3.
Profitability (X) → Marketing (Y); Marketing (Y). Conclusion: Profitability (X).
The phrase 'is required for' introduces a necessary condition. Affirming it to prove the sufficient condition is a Flawed Reversal.
4
Diagram Argument 4.
Non-compete (X) → Binding (Y); ~Non-compete (~X). Conclusion: ~Binding (~Y).
The phrase 'Provided that' introduces a sufficient condition. Denying it to disprove the necessary condition is a Flawed Negation.

Key Concept

Identifying formal conditional logic structures (valid deductions vs. formal flaws) in natural language arguments.
Question 10Question →

If a software application incorporates end-to-end encryption, it cannot be effortlessly intercepted by third-party eavesdroppers. The new messaging platform 'ChatSecure' cannot be effortlessly intercepted by third-party eavesdroppers. Therefore, 'ChatSecure' must incorporate end-to-end encryption.

Which one of the following arguments contains a flawed pattern of reasoning most similar to the one exhibited in the argument above?

Show answer & explanation

Answer: If a novel wins the prestigious Booker Prize, it will experience a massive surge in sales. The debut novel 'Echoes' recently experienced a massive surge in sales. Hence, 'Echoes' must have won the Booker Prize.

Answer

The argument concluding that a novel must have won the Booker Prize because it experienced a surge in sales.
The correct answer accurately mirrors the illegal reversal (affirming the consequent) found in the stimulus. The stimulus establishes a conditional statement 'If A (encryption), then B (no interception)', notes that B occurred, and incorrectly concludes A must have occurred. Similarly, the correct choice establishes 'If A (Booker Prize), then B (sales surge)', notes that B occurred (Echoes had a sales surge), and identically missteps by concluding A occurred (Echoes won the Booker).

Step-by-Step Solution

1
Analyze the logical structure of the stimulus argument.
Premise 1: If end-to-end encryption (A), then cannot be intercepted (B). Premise 2: ChatSecure cannot be intercepted (B). Conclusion: Therefore, ChatSecure uses end-to-end encryption (A).
Breaking down the argument into abstract conditional components makes it easier to identify the structural flaw.
2
Identify the specific logical flaw committed in the stimulus.
The argument commits a conditional logic error known as an illegal reversal, or affirming the consequent. It incorrectly assumes that because the necessary condition (B) is met, the sufficient condition (A) must have occurred.
Knowing the exact name and mechanism of the flaw is required to find its parallel.
3
Evaluate the answer choices to find the exact structural match.
The argument regarding the Booker Prize follows the exact same pattern: If Booker Prize (A), then sales surge (B). Sales surged (B). Therefore, Booker Prize (A).
Parallel flaw questions require matching the underlying abstract structure exactly, regardless of whether the subject matter is entirely different.

Key Concept

Illegal Reversal (Affirming the Consequent) in Conditional Logic
Estimated Time:1m 30s
Question 11Question →

Read the four short passages below, drawn from diverse fields of study. Each passage contains a specific error in reasoning. Select the abstract description that best identifies the structural flaw present in each argument.

Click a left item, then click its matching right item

Items

If a cryptographic network implements decentralized hash verifications, it will successfully repel coordinated denial-of-service attacks. The 'Aegis' network recently repelled a massive, coordinated denial-of-service attack. Therefore, the Aegis network must have implemented decentralized hash verifications.
Every individual vocalization identified in the newly recorded dialect of the isolated mountain community is a variation of standard lowland vowels. Consequently, the dialect as a whole must simply be a variation of the standard lowland language.
Whenever ocean temperatures drop below the historical average in the equatorial Pacific, migratory patterns of the Bluefin tuna are severely disrupted. Forecasts indicate that equatorial Pacific temperatures will remain well above the historical average this year. We can therefore conclude that the migratory patterns of the Bluefin tuna will not be severely disrupted.
Archaeological surveys demonstrate that in medieval settlements where rye cultivation was prevalent, incidences of joint disease were remarkably low. This strongly suggests that a diet rich in rye actively prevents the onset of joint disease.

Matches

Show answer & explanation

Answer

The cryptographic network argument pairs with inferring a condition from its result; the dialect argument pairs with drawing conclusions about a whole from its parts; the oceanography argument pairs with assuming an outcome is avoided if one sufficient condition is absent; and the archaeology argument pairs with mistaking correlation for causation.
Each abstract description perfectly captures the logical error committed in its corresponding argument without relying on the specific vocabulary of the argument's topic. By mapping the conditional, compositional, and causal errors to their respective formal descriptions, the underlying flaw is correctly identified.

Step-by-Step Solution

1
Analyze the cryptographic network argument.
Identified structure: A ensures B. B occurred. Therefore, A occurred.
This reveals an 'Illegal Reversal' flaw, which confuses a sufficient condition with a necessary condition.
2
Analyze the linguistic dialect argument.
Identified structure: All parts (vocalizations) have trait X. Therefore, the whole (dialect) is X.
This represents the 'Fallacy of Composition', attributing a property of parts to the entirety of a system.
3
Analyze the oceanography argument.
Identified structure: A causes B. Not A. Therefore, Not B.
This represents an 'Illegal Negation' flaw, incorrectly assuming that avoiding one sufficient trigger guarantees the outcome will not happen.
4
Analyze the archaeology argument.
Identified structure: Phenomenon A and Phenomenon B occur together. Therefore, A causes B.
This matches a basic correlation-to-causation fallacy.

Key Concept

Identifying abstract logical flaws across different topics by recognizing underlying structural patterns.
Estimated Time:2m 0s
Question 12Question →

For any bureaucratic system to achieve total efficiency, it must either eliminate its redundant departments or fully automate its record-keeping. However, a bureaucratic system can fully automate its record-keeping only if it secures a massive influx of external funding. Given that no bureaucratic system ever secures a massive influx of external funding, a bureaucratic system can achieve total efficiency only if it eliminates its redundant departments.

Which of the following arguments is most similar in its pattern of reasoning to the argument presented above?

Show answer & explanation

Answer: For a new tech startup to survive its first year, it must either secure venture capital or achieve immediate profitability. A startup can secure venture capital, however, only if it possesses a patented technology. Given that no new tech startup ever possesses a patented technology in its first year, a startup can survive its first year only if it achieves immediate profitability.

Answer

The argument concerning the tech startup's survival.
The correct answer accurately replicates the complex deductive chain of the stimulus: A necessary condition containing a disjunction is presented, followed by a secondary necessary condition for one of those disjuncts. That secondary condition is then universally denied, triggering Modus Tollens to eliminate one half of the disjunction. Finally, a valid conclusion is drawn stating that the initial event now strictly requires the remaining half of the disjunction. Both the logical flow and the universal/conditional phrasing match exactly.

Step-by-Step Solution

1
Map the formal logic of the stimulus.
Efficiency (E) -> Eliminate (R) OR Automate (A). Automate (A) -> Funding (F). Not Funding (~F). Conclusion: Efficiency (E) -> Eliminate (R).
Identifying the abstract deductive structure is necessary before comparing it to the answer choices.
2
Analyze the modality and quantifiers of the stimulus.
The stimulus uses universal certainty ('For any', 'ever', 'only if') and ends with a conditional rule rather than an absolute factual claim.
A parallel argument must match not only the logical chain but also the strength of its claims.
3
Evaluate the options against the mapped architecture.
The option about tech startups maps perfectly: Survive (S) -> Venture Capital (V) OR Profitability (P). Venture Capital (V) -> Patent (T). Not Patent (~T). Conclusion: Survive (S) -> Profitability (P).
This confirms the structural match without being distracted by subject matter.

Key Concept

Parallel Valid Structure (Disjunctive Syllogism combined with Modus Tollens)
Question 13Question →

If a plant is a healthy fern, then it thrives in high humidity. This particular houseplant does not thrive in high humidity. Therefore, this houseplant is not a healthy fern.

Which one of the following arguments is most similar in its logical structure to the argument presented above?

Show answer & explanation

Answer: If a building is a modern skyscraper, then it requires a deep steel foundation. The new city library does not require a deep steel foundation. Therefore, the new city library is not a modern skyscraper.

Answer

The argument concerning the modern skyscraper and the deep steel foundation.
The correct answer precisely duplicates the valid Modus Tollens structure found in the stimulus. The stimulus establishes a conditional rule (If Healthy Fern -> High Humidity), observes the absence of the necessary condition (No High Humidity), and validly concludes the absence of the sufficient condition (Not a Healthy Fern). The correct argument mirrors this exactly: It sets a rule (If Skyscraper -> Steel Foundation), observes the absence of the necessary condition (No Steel Foundation), and concludes the absence of the sufficient condition (Not a Skyscraper).

Step-by-Step Solution

1
Analyze the logical structure of the stimulus argument.
The stimulus uses a valid 'Modus Tollens' structure: Premise 1 is 'If A (fern), then B (humidity)'. Premise 2 is 'Not B (does not thrive in humidity)'. The Conclusion is 'Therefore, Not A (not a fern)'.
Identifying the formal structure of the original argument is required to find its parallel match.
2
Evaluate the options for a matching valid structure.
The option about the skyscraper states: 'If A (skyscraper), then B (steel foundation). Not B (no steel foundation). Therefore, Not A (not a skyscraper).'
This structural match perfectly duplicates the valid deduction of the stimulus.
3
Eliminate options with flawed reasoning or mismatched quantifiers.
Options exhibiting illegal reversal, illegal negation, or using 'most' instead of 'if' are eliminated, regardless of subject matter.
Parallel valid reasoning requires exact duplication of both the deductive architecture and the certainty level.

Key Concept

Parallel Valid Structure (Modus Tollens)
Question 14Question →

Match each flawed argument on the left with the abstract description of its logical error on the right.

Click a left item, then click its matching right item

Items

If a commercial airline upgrades its fleet to next-generation jets, its fuel efficiency will inevitably improve. Skyline Airways has reported improved fuel efficiency this year. Therefore, Skyline Airways must have upgraded its fleet to next-generation jets.
Recent labor market data reveals that regions with the highest number of co-working spaces also experience the highest rates of freelance job growth. Therefore, opening more co-working spaces directly causes freelance job growth in a region.
Every individual brick used in the exterior facade of the new stadium is extremely light and can be easily lifted by one person. Consequently, the fully assembled stadium facade must also be extremely light and easily lifted by one person.
The national constitution guarantees the right to a free press. Since the dominant media conglomerate charges exorbitant subscription fees for its daily newspaper, it is clearly violating the constitution.

Matches

Show answer & explanation

Answer

The correct matches are: the airline argument matches the sufficient/necessary flaw, the labor market argument matches the correlation/causation flaw, the stadium argument matches the whole/part flaw, and the newspaper argument matches the shifting meaning flaw.
Each argument contains a specific, distinct logical error that maps exactly to one abstract description. The airline argument illegally reverses a conditional statement. The labor market argument confuses correlation for causation. The stadium argument commits a part-to-whole composition error. Finally, the newspaper argument equivocates on the meaning of the word 'free'.

Step-by-Step Solution

1
Analyze the airline argument for its logical structure.
The argument assumes that since the result (fuel efficiency) happened, the stated trigger (jet upgrades) must have been the cause.
Identifying the formal logic structure reveals an illegal reversal of a conditional statement.
2
Analyze the labor market argument.
The argument takes an observed coincidence (co-working spaces and job growth happening together) as absolute proof of causation.
Separating the premise (correlation) from the conclusion (causation) isolates the causal flaw.
3
Analyze the stadium argument.
The argument assumes a property of the individual bricks (being light) must apply to the entire completed facade.
Recognizing the shift in scope from components to the aggregate identifies a composition flaw.
4
Analyze the newspaper argument.
The argument shifts from 'free' meaning unrestricted speech to 'free' meaning no financial cost.
Tracking the definition of key terms uncovers an equivocation flaw.

Key Concept

Identifying abstract descriptions of logical flaws (Parallel Flaw)
Question 15Question →

The following arguments each demonstrate a common logical vulnerability. Which abstract description best identifies the flawed pattern of reasoning used in each argument?

Click a left item, then click its matching right item

Items

A thriving marine ecosystem invariably features a diverse population of apex predators, as these predators regulate the populations of smaller marine life. Survey data from the Emerald Reef indicates a highly diverse population of apex predators currently inhabits the area. Therefore, the Emerald Reef must be a thriving marine ecosystem.
To stabilize the endangered wolf population, wildlife officials must introduce captive-bred wolves into the wild. After all, the only other suggestion—restricting human development in the wolves' natural habitat—has been repeatedly rejected by the regional legislature. Thus, introducing captive-bred wolves is the only path forward.
The globally renowned Horizon Tech Corporation has consistently been recognized as the most innovative tech company of the decade, pioneering breakthroughs in quantum computing and artificial intelligence. Consequently, Elias Vance, who works as a junior accountant at Horizon Tech, must be an exceptionally innovative employee.
A comprehensive dietary study found that individuals who consume high amounts of artificially sweetened beverages suffer from chronic fatigue syndrome at triple the rate of those who do not. This demonstrates that consuming artificially sweetened beverages directly contributes to the onset of chronic fatigue syndrome.

Matches

Show answer & explanation

Answer

The arguments logically pair as follows: The marine ecosystem argument matches the description of confusing a necessary condition with a sufficient one. The wolf population argument matches the description of a false dilemma. The tech company argument matches the description of a part-to-whole (division) error. The dietary study argument matches the description of confusing correlation with causation.
Each argument contains exactly one distinct logical error that perfectly mirrors the corresponding abstract description. The marine ecosystem argument demonstrates an illegal reversal (necessary vs. sufficient). The wolf argument demonstrates a false dichotomy. The tech company argument demonstrates a flaw of division. The dietary argument demonstrates a correlation-causation fallacy.

Step-by-Step Solution

1
Analyze the marine ecosystem argument.
Identified that the premise states 'thriving ecosystem -> diverse predators', but the conclusion reverses this to 'diverse predators -> thriving ecosystem'.
Recognizing conditional logic errors is crucial for matching it to the abstract description regarding necessary and sufficient conditions.
2
Analyze the wolf population argument.
Noted that it dismisses one option and automatically defaults to a second option, ignoring the possibility of any third alternative.
This structural pattern defines a false dilemma, matching the description about unstated assumptions regarding alternatives.
3
Analyze the tech company argument.
Observed that it attributes the broad characteristic of a company ('innovative') to a specific individual part of that company (an accountant).
This is the classic definition of the logical flaw of division, matching the description of presuming a collective attribute applies to constituent parts.
4
Analyze the dietary study argument.
Recognized that it jumps from a 'found correlation' (triple the rate) to a 'direct contribution' (causation) without eliminating other factors.
This error directly corresponds to the description of taking statistical correlation as definitive proof of causation.

Key Concept

Identifying and abstracting logical reasoning errors
Question 16Question →

According to the city's new preservation guidelines, if a building is to be designated as a historical landmark, it must preserve its original exterior facade and be structurally reinforced against earthquakes. Furthermore, if a building is constructed of unreinforced masonry, it cannot be structurally reinforced against earthquakes. The old municipal library is constructed of unreinforced masonry. Therefore, the old municipal library will not be designated as a historical landmark.

Which of the following arguments exhibits a pattern of reasoning most logically parallel to that demonstrated in the argument above?

Show answer & explanation

Answer: According to the hospital's protocol, if a patient is to be prescribed the experimental medication, they must possess normal kidney function and be closely monitored by a specialist. If a patient resides in a rural area, they cannot be closely monitored by a specialist. Patient Jones resides in a rural area. Therefore, Patient Jones will not be prescribed the experimental medication.

Answer

The argument concerning Patient Jones being denied the experimental medication due to residing in a rural area.
The stimulus argument employs a valid form of conditional reasoning using a conditional chain to trigger the contrapositive of a compound necessary condition. It states that two conditions are necessary for a building to become a landmark (A → B and C). It then introduces a second conditional rule establishing that a certain characteristic prevents one of those necessary conditions (D → ~C), and applies this to a specific case (X is D) to validly conclude the sufficient condition cannot occur (X is ~A). The correct answer perfectly mirrors this structure: it establishes two necessary conditions for a medication prescription, introduces a second rule showing a characteristic prevents one of those conditions, and validly concludes the medication will not be prescribed for a patient with that characteristic.

Step-by-Step Solution

1
Analyze the logical structure of the primary conditional premise in the stimulus.
The stimulus establishes a conditional rule with a compound necessary condition: Landmark → (Preserve Facade AND Structural Reinforcement).
Identifying the formal symbolic structure of the primary rule is required to find an exact structural match.
2
Determine the deduction pattern used to reach the conclusion in the stimulus.
The argument introduces a secondary rule (Unreinforced Masonry → ~Structural Reinforcement) and applies it to a specific case (Library is Unreinforced Masonry) to prove one necessary condition is not met. It then validly concludes the sufficient condition cannot occur (~Landmark).
Parallel reasoning requires matching the specific conditional chain and the valid reasoning pattern leading to the conclusion.
3
Evaluate the answer choices to find the identical logical skeleton.
The correct choice must feature: A → (B AND C); D → ~C; X is D; therefore, X is ~A.
Eliminating choices with structural mismatches (single condition, 'or' instead of 'and') or logical flaws (illegal reversal/negation) is necessary to isolate the perfect match.
4
Identify the matching option.
The hospital protocol argument matches exactly: Prescribed → (Kidney Function AND Monitored); Rural → ~Monitored; Jones is Rural; therefore, Jones is ~Prescribed.
This option shares the exact validity, conditional complexity, and chain structure of the stimulus argument.

Key Concept

Parallel Conditional Logic
Question 17Question →

Match each causal argument on the left to the formal description of its causal reasoning structure or fallacy profile on the right.

Click a left item, then click its matching right item

Items

Observational studies show that individuals who frequently consume artificial sweeteners experience higher rates of metabolic syndrome. It is therefore evident that metabolic syndrome is induced by the consumption of these sweeteners.
The recent spike in the inflation rate cannot be attributed to increased consumer spending, as retail sales have plummeted. Furthermore, supply chain disruptions have fully resolved. Consequently, the aggressive expansion of the money supply must be driving the inflation.
Paleontologists have noted that fossil beds containing the remains of species X almost always contain the remains of species Y. Clearly, the presence of species X created an ecological environment that allowed species Y to thrive.
A reduction in corporate tax rates inevitably leads to increased capital investment. This surge in investment subsequently creates a higher demand for skilled labor, driving up average wages. Hence, corporate tax cuts are ultimately responsible for rising wages.

Matches

Show answer & explanation

Answer

The artificial sweetener argument matches the reverse causation flaw. The inflation argument matches the alternative elimination structure. The fossil bed argument matches the common cause flaw. The tax cut argument matches the valid intermediate causal chain.
Each argument maps perfectly to a classic LSAT causal structure. The sweetener argument fails to see that illness drives the diet choice (reverse causation). The inflation argument uses the process of elimination. The fossil argument ignores that a shared habitat (third factor) brought the species together. The tax argument successfully builds a multi-step causal chain.

Step-by-Step Solution

1
Analyze the artificial sweetener argument.
Identified a correlation-to-causation flaw where the effect (metabolic syndrome) likely causes the alleged cause (consuming diet products). Matches the 'opposite direction' profile.
Recognizing directionality flaws is critical when behavioral choices are correlated with health outcomes.
2
Examine the inflation argument.
Identified a structure that rules out 'consumer spending' and 'supply chain disruptions' to conclude that 'money supply' is the cause. Matches the 'eliminating alternative explanations' profile.
This is a formally valid way to establish a cause, provided all other plausible alternatives are actually eliminated.
3
Evaluate the fossil bed argument.
Identified a spatial correlation between two species, leaping to the conclusion that one caused the other. Matches the 'overlooking a common underlying cause' (shared habitat) profile.
When two non-causally linked entities appear together frequently, a third environmental factor is usually responsible for both.
4
Assess the tax cut argument.
Identified a step-by-step logical progression (A causes B, B causes C, C causes D). Matches the 'valid sequence of intermediate causal links' profile.
Understanding causal sufficiency requires tracking how a primary trigger flows through intermediate steps to a final result.

Key Concept

Parallel Causal Reasoning Profiles
Question 18Question →

The software company must either transition to a subscription model or release a major update. If the company releases a major update, it will be forced to delay the launch of its subsidiary project. However, the board of directors has guaranteed that the company will definitely not delay the launch of its subsidiary project. Therefore, the company must transition to a subscription model.

Which of the following arguments exhibits a pattern of reasoning most similar to that exhibited by the argument above?

Show answer & explanation

Answer: A newly classified insect species is either a pollinator or a parasite. If it is a parasite, it must possess a specialized feeding appendage. Entomologists have confirmed that this species does not possess a specialized feeding appendage. Thus, the species is a pollinator.

Answer

The argument about the newly classified insect species perfectly maps the deductive structure of the original stimulus.
The original argument uses a valid deductive structure combining a disjunction (A or B) with a conditional (If B, then C) and a denial of the necessary condition (Not C). By modus tollens, we know Not B is true. Therefore, the remaining disjunct (A) must be true. The correct option identically maps this structure: it presents two possibilities for the insect species, establishes a conditional requirement for one of them, observes the absence of that requirement to eliminate it, and correctly concludes the remaining possibility.

Step-by-Step Solution

1
Analyze the logical structure of the stimulus argument.
The argument establishes a disjunction (transition OR update), a conditional rule (update -> delay), and a factual premise denying the necessary condition (~delay). It concludes with the remaining disjunct (transition).
Breaking down the stimulus into formal logic is required to find an exact structural match.
2
Evaluate the deductive validity of the stimulus.
The argument is valid. It uses Modus Tollens to eliminate one possibility: since the update guarantees a delay, and there is no delay, there is no update. Thus, the company must transition.
Parallel reasoning questions require the correct answer to have the exact same level of validity as the stimulus.
3
Examine each answer choice for the identical 'Disjunction + Modus Tollens' structure.
The option discussing the insect species matches perfectly: it sets up a disjunction (pollinator OR parasite), a conditional (parasite -> appendage), denies the consequence (~appendage), and concludes the other disjunct (pollinator).
The correct answer must match the structural architecture without introducing different quantifiers or logical fallacies.

Key Concept

Parallel Valid Structure (Disjunctive Syllogism and Modus Tollens)
Question 19Question →

Any city that successfully implements a comprehensive public transit system will see a significant reduction in traffic congestion. Therefore, since the city of Oakhaven has recently seen a significant reduction in traffic congestion, it must have successfully implemented a comprehensive public transit system.

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

Show answer & explanation

Answer: All successful startup founders possess a high tolerance for risk. Thus, because Julian possesses a high tolerance for risk, he must be a successful startup founder.

Answer

The option stating that Julian must be a successful startup founder because he possesses a high tolerance for risk.
The original argument commits an illegal reversal flaw: it treats a necessary condition (reduced congestion) as if it were a sufficient condition, arguing that because the result occurred, the specific trigger must have caused it. The correct option perfectly mirrors this structure by establishing that being a successful founder guarantees high risk tolerance, and then flawed inferences that Julian's high risk tolerance guarantees he is a successful founder.

Step-by-Step Solution

1
Analyze the logical structure and identify the flaw in the stimulus argument.
The stimulus establishes a conditional premise: If a city implements a transit system (A), it sees reduced congestion (B). It then observes the result (B) and concludes the condition (A). This is an illegal reversal: assuming that a necessary condition is a sufficient one.
Correctly identifying the abstract structure of the flaw is required to find its parallel among the answer choices.
2
Evaluate the answer choices to find the one with the exact same structural flaw (Illegal Reversal: If A then B; B, therefore A).
The correct argument states: If one is a successful founder (A), one has high risk tolerance (B). Julian has high risk tolerance (B), therefore Julian is a successful founder (A).
Matching the abstract logical format ensures the correct answer contains an identical pattern of faulty reasoning, ignoring differences in subject matter.

Key Concept

Parallel Flaw - Illegal Reversal
Question 20Question →

Some of the bronze artifacts excavated at the ancient city of Oakhaven contain trace amounts of zinc. Furthermore, every bronze artifact containing trace amounts of zinc is highly susceptible to rapid oxidation when exposed to humid air. Therefore, some of the bronze artifacts excavated at Oakhaven are highly susceptible to rapid oxidation when exposed to humid air.

Which of the following arguments exhibit a pattern of reasoning logically parallel to that in the argument above? Select all that apply.

Select all that apply

Show answer & explanation

Answer: Some of the corporate bonds issued by Vertex Inc. have been downgraded to junk status. Any corporate bond downgraded to junk status carries a significant default risk. Thus, some of the corporate bonds issued by Vertex Inc. carry a significant default risk.; Every tropical cyclone forming in the eastern basin experiences intense wind shear. Since some weather systems tracked by the national observatory are tropical cyclones forming in the eastern basin, it follows that some weather systems tracked by the national observatory experience intense wind shear.

Answer

The correct arguments are those discussing Vertex Inc. corporate bonds and tropical cyclones.
The stimulus presents a valid syllogism combining an existential quantifier ('some') with a universal quantifier ('every/all') to yield an existential conclusion: Some A are B; All B are C; Therefore, Some A are C. The correct answers both perfectly replicate this valid transitive chain. The corporate bond scenario uses the exact same order of premises, while the tropical cyclone scenario reverses the order of the premises but maintains the identical logical chain, which is completely acceptable in parallel reasoning.

Step-by-Step Solution

1
Analyze the logical structure of the stimulus.
Premise 1: Some A (bronze artifacts) are B (contain zinc). Premise 2: All B (contain zinc) are C (susceptible to oxidation). Conclusion: Some A (bronze artifacts) are C (susceptible to oxidation).
Identifying the formal logic and quantifier chain is necessary to find identical parallel structures.
2
Evaluate the validity of the stimulus argument.
The argument is a valid deduction. If a subgroup of A belongs entirely to B, and all of B belongs to C, then that subgroup of A must also belong to C.
A parallel argument must share the same validity status (valid or invalid) as the original.
3
Examine the answer choices for matching structure and validity.
The argument about corporate bonds follows 'Some A are B, All B are C -> Some A are C'. The argument about tropical cyclones follows 'All B are C, Some A are B -> Some A are C'. Both perfectly match the logical chaining and quantifier scope.
To be parallel, the options must chain a 'some' relationship through a universal 'all/any/every' condition to reach a valid 'some' conclusion.

Key Concept

Parallel Quantifier Logic requires matching not only the structural relationships between terms but also the precise strength of the quantifiers used (e.g., distinguishing 'some' from 'most' or 'all') and the overall validity of the deduction.
Page 1 / 5Next
Parallel Reasoning Practice Questions — LSAT | Examkin