Examkin

Logical Reasoning

666 soru

Tüm türler666Çoktan seçmeli343Çoklu seçim54Doğru / Yanlış70Eşleştirme166Sıralama18Boşluk doldurma10Kısa cevap5
Soru 301Soru →

Patent Attorney: For an applicant to be granted an expedited review under the national patent office's green technology initiative, the proposed invention must demonstrate a documented reduction in carbon emissions and utilize exclusively non-toxic manufacturing components. The prototype submitted by SolarClean Industries has been verified to reduce carbon emissions by thirty percent and contains no toxic materials. Thus, SolarClean's patent application will definitely be granted expedited review.

The patent attorney's argument is most vulnerable to criticism on the grounds that it

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Cevap: infers that a specific outcome is guaranteed merely because the prerequisites for that outcome have been satisfied

Cevap

The argument is flawed because it treats meeting the necessary eligibility requirements as sufficient to guarantee that the application will be granted expedited review.
The attorney establishes that reducing carbon emissions and using non-toxic materials are mandatory prerequisites ('must demonstrate') for expedited review. However, showing that SolarClean satisfies these baseline criteria only establishes that it is eligible; it does not guarantee that expedited review will be granted, as other unstated criteria or procedural limits could prevent approval. The argument erroneously treats necessary conditions as sufficient.

Adım Adım Çözüm

1
Identify the premises and the conclusion of the argument.
Premise 1 states that obtaining expedited review requires demonstrating emission reductions and using non-toxic components (necessary conditions). Premise 2 verifies that SolarClean satisfies both conditions. The conclusion asserts that SolarClean's application will definitely be granted expedited review.
Deconstructing the argument into its constituent structural elements isolates the relationship between the evidence provided and the claim made.
2
Analyze the logical link between the premises and the conclusion to identify the vulnerability.
The phrase 'must demonstrate... and utilize' sets up necessary prerequisites for expedited review. Satisfying prerequisites makes an applicant eligible, but does not guarantee approval (sufficient condition).
Identifying the modal and conditional mismatch reveals the core reasoning error.
3
Match the identified flaw with the option that accurately describes this vulnerability without bringing in outside assumptions.
The option stating that the argument infers a guaranteed outcome merely from the satisfaction of prerequisites precisely captures this necessary-versus-sufficient confusion.
This accurately names the logical fallacy committed in the stimulus.

Anahtar Kavram

Confusing Necessary and Sufficient Conditions (Conditional Reversal)
Tahmini Süre:1m 15s
Soru 302Soru →

Every deep-sea expedition in the Clarion Trench that detects hydrothermal chimney deposits performs isotope mass spectrometry on its sediment cores. Any expedition that performs isotope mass spectrometry on its sediment cores publishes its stratigraphy dataset in the Open Ocean Registry, unless it is funded by a private mineral consortium. Furthermore, no expedition that publishes its stratigraphy dataset in the Open Ocean Registry fails to submit its benthic fauna logs to the International Seabed Authority. Last year, the research vessel Astraea conducted an expedition in the Clarion Trench, detected hydrothermal chimney deposits, and did not submit its benthic fauna logs to the International Seabed Authority.

Based on the statements above, which of the following statements must be true? (Select all that apply.)

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Cevap: The research vessel Astraea performed isotope mass spectrometry on its sediment cores.; The research vessel Astraea was funded by a private mineral consortium.

Cevap

The statements establishing that Astraea performed isotope mass spectrometry on its sediment cores and that Astraea was funded by a private mineral consortium must both be true.
The deduction that Astraea performed isotope mass spectrometry follows directly from the first premise. The deduction that Astraea was funded by a private mineral consortium is derived by combining the contrapositive of the logging rule with the conditional exception in the second premise.

Adım Adım Çözüm

1
Apply the first premise to the factual case of Astraea.
Since Astraea operated in the Clarion Trench and detected hydrothermal chimney deposits, it is logically guaranteed that Astraea performed isotope mass spectrometry on its sediment cores.
The rule states that detecting chimney deposits in the Clarion Trench is sufficient to guarantee isotope mass spectrometry.
2
Take the contrapositive of the third premise regarding benthic fauna logs.
Since Astraea did not submit benthic fauna logs to the International Seabed Authority, Astraea did not publish its stratigraphy dataset in the Open Ocean Registry.
The third premise states that publishing in the registry guarantees log submission; failing to submit logs proves non-publication.
3
Synthesize the results with the second conditional premise ('unless' condition).
Because Astraea performed isotope mass spectrometry but did not publish in the registry, Astraea must be funded by a private mineral consortium.
Expeditions performing spectrometry must publish unless funded by a private mineral consortium; hence, non-publishing spectrometry expeditions must be privately funded.

Anahtar Kavram

Multi-step conditional chaining with contrapositive deduction and exception ('unless') resolution
Soru 303Soru →

Every container vessel docking at Port Vane must either utilize shore power while berthed or burn certified ultra-low emission fuel. Any vessel that burns certified ultra-low emission fuel is subject to mandatory fuel auditing by the maritime authority unless it possesses an active green-flag certification. Yesterday, the container vessel Meridian Star docked at Port Vane, did not utilize shore power while berthed, and does not possess an active green-flag certification.

If the statements above are true, which one of the following must also be true?

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Cevap: The Meridian Star is subject to mandatory fuel auditing by the maritime authority.

Cevap

The Meridian Star is subject to mandatory fuel auditing by the maritime authority.
The conclusion that the Meridian Star is subject to mandatory fuel auditing strictly follows from combining the premises. Under Port Vane rules, every docking vessel must use shore power or burn ultra-low emission fuel. Since the Meridian Star docked and did not use shore power, it had to burn ultra-low emission fuel. Under the second rule, burning that fuel triggers mandatory fuel auditing unless the ship has green-flag certification. Because the Meridian Star lacks this certification, the audit is strictly required.

Adım Adım Çözüm

1
Analyze the first requirement for vessels docking at Port Vane.
Docking Vessel → Shore Power OR Ultra-Low Emission Fuel.
Establishes a disjunctive requirement for all docking container vessels.
2
Apply the facts regarding the Meridian Star to the first rule.
Because the Meridian Star docked at Port Vane and did not use shore power, it must have burned certified ultra-low emission fuel.
Eliminating one disjunct necessitates the truth of the remaining disjunct.
3
Evaluate the auditing condition given the vessel's status.
Ultra-Low Emission Fuel AND No Green-Flag Certification → Mandatory Fuel Audit.
Since the Meridian Star satisfies both conditions (burned the fuel and lacks the certification), the mandatory audit necessarily follows.

Anahtar Kavram

Deductive Conditional Chaining and Disjunctive Elimination
Tahmini Süre:1m 15s
Soru 304Soru →

Nutritionist: A recent study observed that households that regularly consume fermented tea report 40 percent fewer seasonal respiratory infections than households that do not consume fermented tea. The beverage contains high concentrations of antioxidants, which support immune function. Therefore, regular consumption of fermented tea directly reduces the likelihood of developing seasonal respiratory infections.

Which of the following, if true, most seriously weakens the nutritionist's argument?

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Cevap: Households that regularly consume fermented tea are significantly more likely to engage in regular exercise and follow hygienic practices than households that do not.

Cevap

Households that regularly consume fermented tea are significantly more likely to engage in regular exercise and follow hygienic practices than households that do not.
The correct response points out that households drinking fermented tea also practice other health-promoting behaviors, such as regular exercise and good hygiene. This provides an alternative explanation for their lower infection rate, demonstrating that the observed benefit may be due to general lifestyle factors rather than the fermented tea itself.

Adım Adım Çözüm

1
Identify the premises and conclusion of the stimulus.
Premise: Fermented tea drinkers report 40% fewer respiratory infections and the tea has antioxidants. Conclusion: Drinking fermented tea directly causes a reduced likelihood of infection.
Isolating the core argument reveals the gap between an observed correlation and a direct causal claim.
2
Identify the underlying logical assumption.
The author assumes there is no confounding variable or alternative explanation accounting for the difference in infection rates between the two groups.
Causal arguments on the LSAT frequently assume that correlation implies causation and that other causative factors are absent.
3
Evaluate the answer choices for a statement that undermines this assumption.
The choice showing that fermented tea consumers also engage in more exercise and better hygiene provides a plausible alternative cause for their fewer infections.
Demonstrating a third variable that accounts for the observed effect severs the direct causal link asserted in the conclusion.

Anahtar Kavram

Alternative Explanations in Causal Reasoning
Soru 305Soru →

Archival conservation standards establish the following protocols for historical documents:
- Any manuscript treated with an aqueous deacidification bath contains alkaline buffer residues.
- If an archival item contains alkaline buffer residues, it cannot be safely housed in a standard cellulose acetate enclosure.
- Every manuscript housed in cold-storage vault Gamma is either a parchment codex or a document that was treated with an aqueous deacidification bath.
- No parchment codex contains alkaline buffer residues.
- Item M-402 is an archival document housed in cold-storage vault Gamma and is safely housed in a standard cellulose acetate enclosure.

Based on the information above, which of the following statements must be true? (Select all that apply)

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Cevap: Item M-402 is a parchment codex.; Item M-402 was not treated with an aqueous deacidification bath.

Cevap

The statements that must be true are that Item M-402 is a parchment codex and that Item M-402 was not treated with an aqueous deacidification bath.
Because Item M-402 is safely housed in a standard cellulose acetate enclosure, the contrapositive of the enclosure rule establishes that it does not contain alkaline buffer residues. In turn, the contrapositive of the deacidification rule proves that Item M-402 was not treated with an aqueous deacidification bath. Finally, because all manuscripts in vault Gamma must either be parchment codices or have received an aqueous deacidification bath, disjunctive elimination confirms that Item M-402 must be a parchment codex.

Adım Adım Çözüm

1
Determine the chemical residue status of Item M-402 using contrapositive reasoning.
Item M-402 does not contain alkaline buffer residues.
The stimulus establishes that containing alkaline buffer residues prevents safe housing in standard cellulose acetate enclosures. Because Item M-402 is safely housed in such an enclosure, the contrapositive guarantees it lacks alkaline buffer residues.
2
Evaluate whether Item M-402 underwent an aqueous deacidification bath.
Item M-402 was not treated with an aqueous deacidification bath.
The stimulus states that any manuscript treated with an aqueous deacidification bath contains alkaline buffer residues. Since Item M-402 has no alkaline buffer residues, the contrapositive establishes that it was not treated with such a bath.
3
Apply disjunctive syllogism to the vault Gamma inventory constraints.
Item M-402 must be a parchment codex.
Every manuscript in vault Gamma must be either a parchment codex or a document treated with an aqueous deacidification bath. Because Item M-402 is in vault Gamma and was not treated with an aqueous deacidification bath, it must be a parchment codex.

Anahtar Kavram

Deductive chaining through contrapositive derivation and disjunctive syllogism
Soru 306Soru →

For each of the following brief argumentative excerpts, identify the statement that most accurately characterizes its central logical defect by matching each excerpt with its corresponding flaw description.

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Öğeler

Mayor: The city council must either approve the proposed commercial zoning ordinance or allow downtown retail to collapse entirely. Because allowing downtown retail to collapse is unacceptable, the council must pass the ordinance.
Publicist: Our firm possesses a legal right to free expression. Because doing what is right cannot be subject to moral condemnation, no one can legitimately criticize our promotional campaign.
Historian: Dr. Vance, an internationally recognized authority in quantum physics, asserts that Bronze Age agrarian trade networks were exclusively riverine. Therefore, we should accept that these ancient trade networks were exclusively riverine.
Architect: Every individual structural beam selected for this municipal pavilion is exceptionally lightweight. It follows that the finished pavilion structure will itself be exceptionally lightweight.

Eşleşmeler

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Cevap

The excerpt regarding municipal zoning matches the description of treating two extremes as the only options; the excerpt regarding the publicist matches the description of conflating legal entitlement with moral correctness; the excerpt regarding ancient trade networks matches the description of appealing to an expert outside their field; and the excerpt regarding pavilion beams matches the description of improperly attributing a property of parts to the whole structure.
Each excerpt demonstrates a classic, well-defined reasoning error: the zoning argument overlooks other solutions by setting up an artificial either/or dichotomy; the publicist argument equivocates on the meaning of 'right'; the history argument relies on an authority speaking outside their specialty; and the pavilion argument commits the composition error by presuming the whole possesses the characteristics of its individual parts.

Adım Adım Çözüm

1
Analyze each argumentative excerpt to identify its underlying premises, stated conclusion, and structural logical gap.
Excerpt 1 forces an either-or dichotomy; Excerpt 2 equivocates on the word 'right'; Excerpt 3 appeals to an unqualified authority; Excerpt 4 commits a composition fallacy (part-to-whole).
Accurately diagnosing the logical fallacy in each excerpt requires isolating how the premises fail to establish the conclusion.
2
Evaluate the abstract flaw descriptions on the right to find the unique match for each diagnosed logical gap.
Each excerpt aligns precisely with one abstract description without ambiguity.
Matching requires pairing concrete argumentative reasoning with standard formal fallacy descriptions.

Anahtar Kavram

Identifying informal and formal fallacies in short arguments, including false dilemma, equivocation, appeal to inappropriate authority, and fallacy of composition.
Soru 307Soru →

The following argumentative excerpts from distinct policy debates each commit a characteristic logical error. Which description on the right correctly identifies the primary reasoning vulnerability of each argument on the left?

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Öğeler

Marine Archaeologist: The university's endowment committee refused to fund our deep-sea excavation on the grounds that deep-water sonar surveys are purely speculative ventures. However, all scientific inquiry begins with speculative hypotheses about unknown phenomena. Therefore, the committee's refusal to fund scientific research is logically inconsistent with academic exploration.
Arborist: City council must immediately order the total removal of every non-native Norway maple across the metropolitan parks. If we do not eradicate every single one of these trees this season, our entire indigenous forest ecosystem will inevitably suffer total collapse within a decade.
Curator: We can definitively date this newly discovered parchment codex to the mid-fourth century BCE. Dr. Vance, the nation's foremost constitutional trial attorney, examined the document's legal phrasing and concluded that it must have originated in that exact era.
Energy Analyst: During the petroleum crises of the 1970s, deep-borehole geothermal extraction was prohibitively expensive compared to fossil fuels. Consequently, geothermal generation will never be economically viable as a baseload power source for modern electrical grids.

Eşleşmeler

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Cevap

The marine archaeologist's argument pairs with trading on an ambiguity between high financial risk and theoretical conjecture; the arborist's argument pairs with failing to consider intermediate courses of action between two extreme alternatives; the curator's argument pairs with relying on the testimony of an expert whose expertise is not relevant to the subject matter; and the energy analyst's argument pairs with treating an economic limitation that held true under past technological conditions as an inherent constraint that must persist indefinitely.
Each argument contains an identifiable logical gap: the excavation argument commits equivocation by altering the definition of 'speculative'; the park arborist sets up a false dichotomy between complete eradication and total collapse; the curator commits an appeal to inappropriate authority by using a trial lawyer to date ancient manuscripts; and the geothermal analyst commits a temporal fallacy by projecting historical 1970s conditions into permanent future truths.

Adım Adım Çözüm

1
Analyze the marine archaeologist's argument for structural flaws
The archaeologist shifts the meaning of 'speculative' from financial investment risk (the committee's usage) to scientific theorizing (academic inquiry), committing equivocation.
Identifying the semantic shift correctly matches this argument with the description regarding ambiguity between financial risk and theoretical conjecture.
2
Analyze the arborist's argument for structural flaws
The arborist assumes an extreme either/or scenario: either complete eradication of non-native trees occurs immediately, or complete ecological ruin results.
This unwarranted bifurcation matches the description regarding failure to consider intermediate alternatives.
3
Analyze the curator's argument for structural flaws
The curator establishes an artifact's physical age solely on the assessment of a constitutional litigator rather than a paleographer or historical linguist.
Citing an authority outside their field of expertise matches the description regarding reliance on irrelevant expertise.
4
Analyze the energy analyst's argument for structural flaws
The analyst takes historical cost data from the 1970s and asserts that geothermal power will never be viable in the future.
Projecting past historical limitations into permanent constraints matches the temporal fallacy description.

Anahtar Kavram

Identifying Fallacy Archetypes in Argumentative Reasoning
Tahmini Süre:2m 30s
Soru 308Soru →

At the Maritime History Museum, every ship model constructed prior to 1850 is housed in a climate-controlled glass display case. Furthermore, any artifact housed in a climate-controlled glass display case is inspected weekly for humidity damage. No artifact inspected weekly for humidity damage is permitted to be loaned out for traveling exhibitions.

If the statements above are true, which one of the following must also be true?

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Cevap: No ship model at the Maritime History Museum constructed prior to 1850 is permitted to be loaned out for traveling exhibitions.

Cevap

No ship model at the Maritime History Museum constructed prior to 1850 is permitted to be loaned out for traveling exhibitions.
The correct option is derived by combining the given conditional rules into a single unbroken chain: if an artifact is a pre-1850 ship model, it must be housed in a climate-controlled case; if it is in such a case, it must receive weekly humidity inspections; and if it receives weekly humidity inspections, it is not permitted to be loaned for traveling exhibitions. Therefore, no pre-1850 ship model can be loaned for traveling exhibitions.

Adım Adım Çözüm

1
Identify and translate the conditional premises into formal logical rules
Rule 1: Pre-1850 ship model → Climate-controlled case; Rule 2: Climate-controlled case → Weekly humidity inspection; Rule 3: Weekly humidity inspection → NOT permitted for traveling exhibitions.
Isolating each conditional relationship clarifies the valid deductive pathways available.
2
Connect the conditional statements into a continuous chain
Pre-1850 ship model → Climate-controlled case → Weekly humidity inspection → NOT permitted for traveling exhibitions.
The necessary condition of each preceding premise matches the sufficient condition of the subsequent premise.
3
Derive the valid deductive conclusion connecting the first term to the last
Pre-1850 ship model → NOT permitted for traveling exhibitions (i.e., no pre-1850 ship model is permitted to be loaned out for traveling exhibitions).
Transitive deduction strictly guarantees this conclusion without requiring any external assumptions.

Anahtar Kavram

Conditional Chaining and Deductive Inference
Tahmini Süre:50s
Soru 309Soru →

Paleoclimatologist: Core samples extracted from the Ellesmere Ice Shelf reveal an abrupt spike in micro-charcoal particle density dating to approximately 8,200 years ago. Because regional boreal forests produce high concentrations of airborne charcoal only during prolonged periods of severe drought and wildfire, researchers conclude that a catastrophic multi-decade megadrought afflicted the adjacent subarctic mainland during this era.

Which of the following statements, if true, most undermine the paleoclimatologist's conclusion? Select all that apply.

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Cevap: Around 8,200 years ago, annual snowfall over the Ellesmere Ice Shelf dropped by over 80 percent, dramatically reducing ice accumulation and concentrating standard atmospheric particulates into dense bands.; Geochemical analysis of the micro-charcoal in the ice layers shows an elemental composition characteristic of basaltic volcanic combustions from a distant ocean ridge rather than organic wood fires.

Cevap

The statements establishing that a severe reduction in snowfall concentrated baseline atmospheric particles and that the charcoal originated from volcanic basalt rather than forest combustion both undermine the conclusion.
The argument assumes that an elevated density of charcoal particles in the ice core must reflect increased mainland forest burning caused by drought. The statement regarding reduced snowfall demonstrates an accumulation artifact where low precipitation concentrates normal baseline particles into high-density layers without any increase in fire activity. Similarly, the statement identifying a volcanic origin demonstrates that the charcoal did not come from burning boreal trees, severing the link to mainland forest conditions.

Adım Adım Çözüm

1
Identify the main conclusion and core premises of the argument.
The premise is that an ice core shows a spike in micro-charcoal density and boreal forests produce high airborne charcoal during severe drought; the conclusion is that a catastrophic megadrought afflicted the adjacent mainland.
Isolating the conclusion allows detection of the key assumptions linking charcoal density in ice to regional drought conditions.
2
Identify the unstated assumptions and vulnerabilities in the author's reasoning.
The author assumes that high particle density reflects higher total charcoal output rather than an ice-accumulation artifact, and that the charcoal necessarily originated from regional mainland forest fires.
Weaken questions require identifying logical gaps or alternative explanations that break the link between the evidence and the conclusion.
3
Evaluate the answer choices to identify all statements that introduce facts undermining these key assumptions.
The statement showing reduced snowfall caused particle concentration and the statement showing a volcanic origin for the charcoal each independently undermine the author's causal claim.
Both findings provide alternative explanations that account for the data without requiring a mainland drought.

Anahtar Kavram

Alternative Causal Explanations and Data Measurement Confounders
Tahmini Süre:1m 30s
Soru 310Soru →

Consider the following argument:

Organizational Psychologist: In an initiative to curtail administrative burnout, a regional hospital network automated its patient intake record-keeping across half of its clinics, while the remaining clinics retained manual data entry. Over the subsequent eighteen months, clinicians at clinics with automated intake reported a 40 percent reduction in administrative fatigue, whereas clinicians at manual clinics reported no change. Thus, automating patient intake records is an effective method for reducing clinician administrative fatigue.

Evaluate whether the following statement is true or false:

The psychologist's conclusion is substantially undermined if, concurrent with the trial period, the hospital network systematically reassigned the most complex, documentation-intensive chronic care patients exclusively to the clinics retaining manual intake.

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Cevap: True

Cevap

True
The evaluated statement is correct in asserting that the argument is substantially weakened. The psychologist infers a direct causal relationship between intake automation and reduced clinician fatigue from a comparative study between automated and manual clinics. However, if the hospital network simultaneously shifted the most documentation-heavy cases away from automated clinics and into manual clinics, the automated clinics experienced an inherent decrease in overall paperwork demands independent of the software. This introduces a major confounding factor that explains the survey results without requiring the software to be effective, thereby undermining the author's causal claim.

Adım Adım Çözüm

1
Deconstruct the stimulus argument into premises and main conclusion
Premise: Automated clinics saw a 40% reduction in fatigue, while manual clinics saw 0%. Conclusion: Automating patient intake is effective at reducing clinician administrative fatigue.
Isolating the core causal claim is essential for evaluating potential vulnerabilities in the reasoning.
2
Identify the unstated causal assumption in the argument
The author assumes that the two groups of clinics were comparable in all other respects affecting administrative workload and that no confounding variable accounts for the observed drop in fatigue.
Causal arguments rely on the assumption that alternative explanations and confounding differences between comparison groups have been ruled out.
3
Evaluate the impact of the supplementary fact on the causal claim
Reassigning complex, documentation-heavy patients exclusively to manual clinics means the automated clinics had a lighter paperwork burden regardless of software efficiency, presenting a viable alternative cause for their reduced fatigue.
Providing a strong rival explanation for the observed outcome directly weakens a causal conclusion.
4
Determine the truth value of the evaluation statement
Because the supplementary fact demonstrates a classic confounding variable flaw and weakens the conclusion, the statement asserting that it substantially undermines the argument is True.
Matching the weakening effect to the statement's claim confirms its validity.

Anahtar Kavram

Identifying confounding variables and alternative explanations to weaken a causal inference
Soru 311Soru →

Match each argument with the fundamental unstated assumption required for its conclusion to be logically justified.

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Öğeler

Archaeologist: A newly excavated clay tablet from ancient Susa bears financial ledger inscriptions in an unusual cuneiform script. Because no scribal school records from Susa mention this script, it must have been developed by visiting merchants rather than local resident scribes.
Urban Planner: Commuters in Metroville will reduce their overall carbon emissions next year if the city replaces its municipal diesel bus fleet with electric buses powered exclusively by the regional power grid.
Software Director: Programmers at our studio who switched from standard physical keyboards to ergonomic split keyboards reported a 40 percent decrease in wrist strain over six months. Therefore, ergonomic split keyboards effectively reduce wrist strain.

Eşleşmeler

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Cevap

The ancient script argument matches the assumption regarding comprehensive scribal documentation; the municipal transit argument matches the assumption regarding electrical grid carbon emissions; and the programmer ergonomics argument matches the assumption excluding alternative workplace factors.
Each paired statement represents an assumption strictly necessary for its respective argument to hold under the Negation Test. In the ancient script argument, claiming that the script was not developed locally because it does not appear in scribal school records depends on the assumption that local development would have resulted in such records. In the urban transit argument, concluding that switching to grid-powered electric buses reduces carbon emissions requires assuming that electricity generation does not offset these savings with equal or greater emissions. In the ergonomic keyboard argument, attributing the reduction in wrist strain to split keyboards depends on assuming that other contemporaneous factors were not primarily responsible.

Adım Adım Çözüm

1
Identify the conclusion and premises for each argument.
Each argument draws a causal or explanatory conclusion from an observational premise, leaving an unstated logical gap.
Isolating the gap between stated evidence and the conclusion reveals what the author takes for granted.
2
Apply the Negation Test to identify which unstated premise is strictly required.
For each correct pair, negating the assumption makes it logically impossible for the premise to justify the conclusion.
A necessary assumption is one whose falsity fatally undermines the argument.
3
Pair each argument with its corresponding necessary presupposition.
Each argument is matched with the precise condition required to defend its conclusion against an obvious vulnerability.
To form valid, necessary pairings across all items.

Anahtar Kavram

A necessary assumption is an unstated premise required for an argument's conclusion to hold; if the assumption is negated, the argument fails.
Soru 312Soru →

According to municipal aquifer management regulations, any commercial facility operating in the Green River basin that extracts more than 50,000 gallons of groundwater daily is classified as a Tier-1 consumer. Every Tier-1 consumer is required to install digital ultrasonic flow meters on all active wellheads. Furthermore, any facility required to install digital ultrasonic flow meters must submit to an annual hydrologic audit. Clearwater Brewing operates in the Green River basin and has not submitted to an annual hydrologic audit.

Statement: Clearwater Brewing does not extract more than 50,000 gallons of groundwater daily.

Cevabı ve açıklamayı göster

Cevap: True

Cevap

True
The conclusion is logically valid via modus tollens across a transitive chain: Extraction > 50,000 gallons leads directly to a mandatory audit; therefore, the absence of an audit necessitates that extraction cannot exceed 50,000 gallons.

Adım Adım Çözüm

1
Diagram the conditional premises provided in the regulatory framework
Extracts >50,000 gallons daily → Tier-1 consumer → Required to install ultrasonic flow meters → Required to submit to annual hydrologic audit.
Establishing the linked conditional relationships clarifies what is logically necessitated by high-volume extraction.
2
Form the contrapositive of the complete conditional chain
No annual hydrologic audit → Not required to install ultrasonic flow meters → Not a Tier-1 consumer → Does not extract >50,000 gallons daily.
A conditional statement is logically equivalent to its contrapositive.
3
Apply the factual information regarding Clearwater Brewing to the contrapositive
Since Clearwater Brewing has not submitted to an annual hydrologic audit, it must be true that it does not extract more than 50,000 gallons of groundwater daily.
Matching the given condition to the contrapositive guarantees the conclusion.

Anahtar Kavram

Deductive Conditional Chaining and Contrapositive Inference
Tahmini Süre:1m 15s
Soru 313Soru →

City Planner: Last year, the city converted one vehicular traffic lane on Market Street into a protected bicycle lane. Over the subsequent twelve months, total retail sales along Market Street increased by 15 percent. Because the bicycle lane increased foot and bicycle traffic directly in front of storefronts, installing dedicated bicycle lanes on commercial corridors is an effective method for boosting local business revenue.

Which of the following statements, if true, each undermine the city planner's conclusion? (Select all that apply.)

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Cevap: During the same twelve-month period, broader regional economic growth caused retail sales across the entire city to rise by an average of 20 percent.; Six months before the bicycle lane was installed, the city reopened a major subway station on Market Street following an extensive two-year renovation.

Cevap

The statements showing that citywide retail sales grew even faster (20 percent) due to general economic growth and that a major subway station reopened on Market Street following renovations each weaken the argument.
The conclusion asserts a direct causal link between the bicycle lane and increased business revenue. The argument is undermined by statements providing plausible alternative explanations: the finding that citywide retail grew by 20 percent indicates Market Street actually underperformed general market trends, and the reopening of a major subway station provides a distinct source of increased foot traffic.

Adım Adım Çözüm

1
Identify the conclusion and the supporting evidence in the stimulus.
The author concludes that installing dedicated bicycle lanes boosts local business revenue, based solely on the correlation between the lane installation and a 15 percent sales increase on Market Street.
Weaken questions require identifying the gap between the stated evidence and the final causal claim.
2
Evaluate each choice to identify alternative explanations or confounding factors.
Two choices introduce external factors—a citywide economic boom and the reopening of a central transit hub—that explain the sales increase independently of the bicycle lane.
Demonstrating that an effect is likely attributable to another cause undermines a causal conclusion.

Anahtar Kavram

Causal reasoning and identifying alternative explanations for an observed correlation
Soru 314Soru →

Agricultural researchers monitored test plots of drought-stressed legumes under varying soil and management conditions. In every plot where mycorrhizal fungal colonization exceeded 40 percent, root nodule nitrogen fixation remained stable throughout the dry season. However, no plot that received synthetic nitrogen fertilizer achieved mycorrhizal fungal colonization above 25 percent. In the southern test valley, all plots managed under the regenerative protocol maintained stable root nodule nitrogen fixation throughout the dry season, but several of these regenerative plots had received synthetic nitrogen fertilizer.

If the statements above are true, which one of the following must also be true?

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Cevap: At least some legume plots with mycorrhizal fungal colonization of 25 percent or less maintained stable root nodule nitrogen fixation throughout the dry season.

Cevap

At least some legume plots with mycorrhizal fungal colonization of 25 percent or less maintained stable root nodule nitrogen fixation throughout the dry season.
The stimulus establishes that several regenerative plots in the southern valley received synthetic fertilizer. By the rule that no plot receiving synthetic fertilizer exceeds 25 percent colonization, these specific plots must have had colonization rates of 25 percent or less. Because all regenerative plots in that valley maintained stable nitrogen fixation throughout the dry season, these specific plots maintained stable fixation despite having colonization rates at or below 25 percent. Thus, it is logically guaranteed that at least some plots with colonization of 25 percent or less maintained stable nitrogen fixation.

Adım Adım Çözüm

1
Extract and formalize the factual premises from the stimulus
Premise 1: Fungal colonization > 40% guarantees stable nitrogen fixation. Premise 2: Synthetic fertilizer guarantees fungal colonization <= 25%. Premise 3: All southern valley regenerative plots had stable nitrogen fixation, and some of these plots received synthetic fertilizer.
Isolating the formal relationships prevents conflating sufficient conditions with necessary conditions.
2
Synthesize the premises regarding the subset of southern valley regenerative plots that received synthetic fertilizer
The regenerative plots that received synthetic fertilizer must have fungal colonization <= 25% (by Premise 2). At the same time, because they are regenerative plots in the southern valley, they maintained stable nitrogen fixation (by Premise 3).
Combining these specific constraints produces a deductively guaranteed overlap.
3
Derive the valid deductive inference
There exist plots (specifically, the fertilized southern valley regenerative plots) that had fungal colonization <= 25% while maintaining stable nitrogen fixation.
This matches the statement that at least some plots with colonization of 25% or less maintained stable nitrogen fixation.

Anahtar Kavram

Quantifier Intersection and Sufficient vs. Necessary Conditions
Tahmini Süre:1m 20s
Soru 315Soru →

Analyze the four logically flawed arguments below. Map each individual argument to the abstract theoretical description that most precisely diagnoses its foundational reasoning vulnerability.

Soldaki öğeye tıklayın, sonra eşleşen sağdaki öğeye tıklayın

Öğeler

The philosopher asserts that human morality is governed by natural laws. Yet, a law is fundamentally a directive issued by a recognized authoritative body. Hence, the philosopher's assertion inadvertently presupposes a supreme legislator, despite his explicitly secular framework.
The mayor insists the new municipal zoning ordinance is fully equitable. Equity inherently requires maximizing the overall economic prosperity of a municipality, an objective this specific ordinance achieves far better than any proposed alternative. Thus, the ordinance clearly constitutes an equitable policy.
Over the past fiscal decade, the proportion of our national budget allocated to infrastructure maintenance has steadily and measurably decreased. It is therefore evident that the government is currently spending less money on maintaining public infrastructure than it did ten years ago.
The foundation of the historic central library is severely compromised. We must either immediately commence a complete demolition and reconstruction or permanently close the facility to the public. Because a complete reconstruction is financially unfeasible this year, the facility must be permanently closed.

Eşleşmeler

Cevabı ve açıklamayı göster

Cevap

The philosopher's argument pairs with the equivocation description; the mayor's argument pairs with the necessary/sufficient confusion; the budget argument pairs with the percentage/amount flaw; and the library argument pairs with the false dilemma description.
Each argument contains a distinct, classic logical fallacy that maps perfectly to one abstract description. The philosopher equivocates on a central term; the mayor confuses necessary and sufficient conditions; the budget analyst conflates relative percentages with absolute amounts; and the library official presents a false dilemma.

Adım Adım Çözüm

1
Deconstruct the philosopher's argument to identify structural shifts.
The argument uses the word 'law' to mean a natural regularity, and then immediately defines 'law' as a human or divine edict.
Tracking key terms reveals the fallacy of equivocation.
2
Analyze the formal logic of the mayor's argument.
Premise 1: Equity -> Maximize Prosperity. Premise 2: Ordinance -> Maximize Prosperity. Conclusion: Ordinance -> Equity. This is a classic 'affirming the consequent' formal flaw.
Translating conditional language ('inherently requires') exposes necessary versus sufficient condition confusions.
3
Evaluate the quantitative jump in the budget argument.
The premise gives a metric in 'proportion' (percentage), but the conclusion claims a reduction in 'money' (absolute amount).
If the total budget expanded vastly over ten years, the absolute money spent could increase even while its percentage share of the budget shrank.
4
Examine the constraints of the library argument.
The argument forces a choice between two extreme poles (demolish vs. close forever) without proving these are the only options.
Identifying restrictive 'either/or' framing helps spot false exclusivity (false dilemmas).

Anahtar Kavram

Identifying abstract structural vulnerabilities in flawed arguments across various domains.
Soru 316Soru →

According to the protocol of the Highfield Agricultural Research Station, every wheat cultivar that demonstrates drought resistance is selected for regional field trials. In addition, no wheat cultivar selected for regional field trials is treated with synthetic nitrogen fertilizers during testing. A newly developed cultivar, Solstice-9, demonstrated drought resistance at the station.

If the statements above are true, which one of the following must also be true on the basis of them?

Cevabı ve açıklamayı göster

Cevap: Solstice-9 is not treated with synthetic nitrogen fertilizers during testing.

Cevap

Solstice-9 is not treated with synthetic nitrogen fertilizers during testing.
The stimulus establishes a transitive conditional chain: drought resistance guarantees selection for regional field trials, and selection for field trials guarantees that no synthetic nitrogen fertilizer is applied during testing. Since Solstice-9 possesses drought resistance, it necessarily follows that Solstice-9 is not treated with synthetic nitrogen fertilizers during testing.

Adım Adım Çözüm

1
Identify the stated conditional relationships and specific factual premise in the stimulus.
Premise 1: Drought Resistance → Selected for Regional Field Trials. Premise 2: Selected for Regional Field Trials → NOT Treated with Synthetic Nitrogen Fertilizer. Fact: Solstice-9 has Drought Resistance.
Establishing the formal conditional rules is necessary to deduce valid deductive inferences.
2
Apply the conditional chain to the specific instance of Solstice-9.
Solstice-9 has Drought Resistance → Solstice-9 is Selected for Regional Field Trials → Solstice-9 is NOT Treated with Synthetic Nitrogen Fertilizer.
A valid deductive syllogism combines universal conditional premises with a specific initiating fact.
3
Select the statement that directly matches the derived necessary conclusion.
The statement specifying that Solstice-9 is not treated with synthetic nitrogen fertilizers during testing is logically guaranteed.
Must Be True questions require a choice that is strictly provable from the premises without additional assumptions.

Anahtar Kavram

Two-step conditional chaining and deductive instantiation
Tahmini Süre:45s
Soru 317Soru →

Premises:
- Every manuscript acquired by the Crestview Historical Society that was created prior to 1700 undergoes spectral imaging before being placed on public exhibition.
- The illuminated manuscript Codex Solaris was created in 1640 and was acquired by the Crestview Historical Society.
- The Codex Solaris is currently on public exhibition at the Crestview Historical Society.

Statement:
Based on the premises above, the Codex Solaris underwent spectral imaging before being placed on public exhibition.

Cevabı ve açıklamayı göster

Cevap: True

Cevap

True
The statement is true because it is a direct deductive consequence of the premises. The stimulus establishes that every manuscript acquired by the society and created before 1700 undergoes spectral imaging before exhibition. Since the Codex Solaris was acquired by the society, created in 1640, and is exhibited, the imaging procedure must have taken place.

Adım Adım Çözüm

1
Formalize the conditional rule established in the stimulus.
Rule: (Acquired by Crestview Society) AND (Created prior to 1700) AND (Placed on public exhibition) → Underwent spectral imaging prior to exhibition.
Identifying the formal structure of the universal premise allows for direct deductive application.
2
Evaluate the facts concerning the Codex Solaris against the antecedent conditions.
The Codex Solaris is acquired by the society, was created in 1640 (which is prior to 1700), and is currently on public exhibition.
All necessary triggers for the conditional rule are fully satisfied by the specific subject.
3
Deduce the necessary outcome.
The Codex Solaris must have undergone spectral imaging prior to exhibition; thus, the statement is conclusively True.
Applying modus ponens directly yields the guaranteed factual conclusion.

Anahtar Kavram

Universal conditional deduction (Modus Ponens)
Soru 318Soru →

Every monoclonal antibody treatment approved by the Federal Health Directorate for autoimmune disorders must either undergo a specialized glycosylation assay or be synthesized exclusively via mammalian expression vectors. No pharmaceutical candidate synthesized exclusively via mammalian expression vectors is exempt from cold-chain temperature logging during cross-border transit. Furthermore, any therapeutic agent subjected to the specialized glycosylation assay exhibits batch-to-batch molecular homogeneity. Nexovira is a monoclonal antibody treatment approved by the Federal Health Directorate for autoimmune disorders that is exempt from cold-chain temperature logging during cross-border transit.

If the statements above are true, which one of the following must also be true on the basis of them?

Cevabı ve açıklamayı göster

Cevap: Nexovira exhibits batch-to-batch molecular homogeneity.

Cevap

Nexovira exhibits batch-to-batch molecular homogeneity.
The stimulus establishes that Nexovira is an approved autoimmune monoclonal antibody treatment that is exempt from transit cold-chain temperature logging. Because synthesis via mammalian expression vectors strictly precludes cold-chain exemptions, Nexovira's exemption guarantees via contrapositive that it was not synthesized via mammalian vectors. Consequently, under the Directorate's approval rule, Nexovira must have undergone the specialized glycosylation assay. Since undergoing this assay guarantees batch-to-batch molecular homogeneity, Nexovira must possess this characteristic.

Adım Adım Çözüm

1
Diagram the formal conditional rules and relationships given in the stimulus.
Approved Treatment → (Glycosylation Assay OR Mammalian Vectors); Mammalian Vectors → NOT Exempt from cold-chain logging; Glycosylation Assay → Molecular Homogeneity.
Establishing explicit conditional chains allows for accurate multi-step deduction.
2
Apply the contrapositive of the cold-chain transit rule to the factual profile of Nexovira.
Because Nexovira is exempt from cold-chain logging, it was NOT synthesized exclusively via mammalian expression vectors.
If a necessary condition is negated, the sufficient condition must also be negated.
3
Evaluate the disjunctive requirement for approved autoimmune treatments and trace the resulting implication.
Since Nexovira is an approved treatment but did not use mammalian expression vectors, it must have undergone the glycosylation assay, which in turn guarantees batch-to-batch molecular homogeneity.
Eliminating one branch of an 'either/or' requirement strictly necessitates the truth of the remaining branch.

Anahtar Kavram

Deductive Conditional Chaining and Disjunctive Syllogism
Tahmini Süre:2m 0s
Soru 319Soru →

To qualify for the Advanced Renewable Energy (ARE) subsidy, a municipal power plant must utilize either geothermal extraction or tidal harnessing technologies, but not both. Any plant that utilizes geothermal extraction must possess a Class 4 seismic mitigation system. However, no plant commissioned prior to 2010 possesses a Class 4 seismic mitigation system. Most municipal power plants commissioned prior to 2010 qualify for the ARE subsidy. Every plant that qualifies for the ARE subsidy and utilizes tidal harnessing technologies is subject to federal maritime jurisdiction.

Which of the following statements must be true based on the information above? (Select all that apply)

Geçerli olan tümünü seçin

Cevabı ve açıklamayı göster

Cevap: Most municipal power plants commissioned prior to 2010 are subject to federal maritime jurisdiction.; At least some municipal power plants subject to federal maritime jurisdiction do not possess a Class 4 seismic mitigation system.

Cevap

The correct statements are that most municipal power plants commissioned prior to 2010 are subject to federal maritime jurisdiction, and that at least some municipal power plants subject to federal maritime jurisdiction do not possess a Class 4 seismic mitigation system.
By tracing the conditional logic: 1) Any plant commissioned prior to 2010 does not have a Class 4 system. 2) Because geothermal extraction requires a Class 4 system, no pre-2010 plant uses geothermal extraction. 3) We are told most pre-2010 plants qualify for the ARE subsidy. 4) To qualify for this subsidy, a plant must use either geothermal or tidal, but not both. Since these pre-2010 ARE-qualifying plants do not use geothermal, they must use tidal technologies. 5) Therefore, most pre-2010 plants both qualify for the ARE subsidy and utilize tidal technologies. 6) Because any plant meeting both these conditions is subject to federal maritime jurisdiction, it must be true that most pre-2010 plants are subject to federal maritime jurisdiction. Furthermore, since these specific plants are pre-2010 (meaning they lack Class 4 systems) and are subject to maritime jurisdiction, it follows necessarily that at least some plants subject to maritime jurisdiction do not possess Class 4 systems.

Adım Adım Çözüm

1
Analyze the conditional relationship between geothermal extraction, seismic mitigation, and plant age.
Since pre-2010 plants lack Class 4 systems, and Class 4 systems are required for geothermal extraction, no pre-2010 plants can utilize geothermal extraction.
This establishes a negative constraint that forces a specific alternative in the next step.
2
Apply the subsidy requirement rules to the pre-2010 plants.
Most pre-2010 plants qualify for the ARE subsidy. Because they cannot use geothermal extraction, they must satisfy the subsidy requirement by utilizing tidal harnessing technologies.
The ARE subsidy requires either geothermal or tidal. Eliminating geothermal leaves only tidal.
3
Synthesize the findings with the rule regarding federal maritime jurisdiction.
Since these 'most' pre-2010 plants both qualify for the ARE subsidy and utilize tidal technologies, they trigger the sufficient condition for federal maritime jurisdiction.
This proves the first correct statement: Most pre-2010 plants are subject to federal maritime jurisdiction.
4
Evaluate the intersection of the established groups to derive further inferences.
Because these specific pre-2010 plants are subject to maritime jurisdiction and lack Class 4 systems, it must be true that at least some plants under maritime jurisdiction lack Class 4 systems.
This proves the second correct statement by combining the established characteristics of the pre-2010 subgroup.

Anahtar Kavram

Must Be True / Most Strongly Supported
Soru 320Soru →

Economist: Five years ago, the municipality of Oakridge instituted a subsidy program covering half the installation costs for businesses that install rooftop rainwater harvesting systems. Over the same five-year period, commercial municipal water consumption in Oakridge dropped by 30 percent. Because the price of municipal water remained constant throughout this period, the subsidy program clearly succeeded in significantly reducing commercial reliance on municipal water.

Which of the following, if true, most seriously undermines the economist's argument?

Cevabı ve açıklamayı göster

Cevap: During the five-year period, two large beverage bottling facilities that had historically accounted for nearly half of Oakridge's total commercial water consumption ceased operations.

Cevap

The argument is most seriously undermined by establishing that during the five-year period, two large beverage bottling facilities accounting for nearly half of Oakridge's commercial water usage ceased operations.
The argument concludes that the subsidy program caused a 30 percent reduction in commercial municipal water consumption based solely on the correlation between the subsidy's implementation and the subsequent decline. The correct answer undermines this causal conclusion by introducing a compelling alternative explanation: the closure of two major beverage bottling facilities that previously comprised nearly half of the entire city's commercial water usage. If those massive consumers closed, total commercial water demand would naturally plummet regardless of whether any other business adopted rainwater harvesting.

Adım Adım Çözüm

1
Identify the argument's premises and main conclusion.
Premises: Oakridge subsidized 50% of rainwater harvesting installations five years ago; commercial water consumption dropped 30% over that period; water prices stayed constant. Conclusion: The subsidy program caused the reduction in commercial water reliance.
Weaken questions require isolating the exact claim the author attempts to prove.
2
Identify the underlying logical flaw or causal gap.
The author commits a correlation-to-causation fallacy by assuming that because the subsidy coincided with a drop in municipal water consumption, the subsidy program must be the cause of that drop, overlooking alternative causes.
To weaken a causal argument, one must introduce an alternative explanation, show a confounding factor, or show the effect occurring without the cause.
3
Evaluate the answer choices for new information that provides a viable alternative cause.
The closure of two water-intensive industrial bottling plants directly accounts for the 30 percent decline in commercial water usage without attributing the change to the harvesting subsidies.
Providing a plausible alternative explanation severs the causal link between the subsidy and the observed reduction in water consumption.

Anahtar Kavram

Alternative Causal Explanations in Weaken Questions
Tahmini Süre:1m 15s
ÖncekiSayfa 16 / 34Sonraki
Logical Reasoning Alıştırma Soruları — LSAT — Sayfa 16 | Examkin