Inference from Text
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GRE Verbal › Inference from Text
A museum conservation lab tested two varnish-removal solvents on a set of 18th-century oil paintings with similar varnish composition. Solvent X removed varnish quickly but, under ultraviolet examination, left faint residues in micro-cracks that required a secondary cleaning step. Solvent Y removed varnish more slowly but left no detectable residue and did not require additional cleaning. When the lab calculated total treatment time, paintings treated with Solvent X took slightly longer on average because the secondary step was time-consuming, though the initial removal was faster. The lab also tracked pigment stability by measuring color shifts before and after treatment; both solvents produced shifts within the lab’s acceptable threshold, but Solvent X showed greater variability across paintings. The lab director must recommend a default solvent for routine use when staff time is limited and minimizing process complexity is a priority.
The passage suggests which of the following?
The residues left by Solvent X will inevitably cause long-term pigment loss in all treated paintings.
Because both solvents meet the color-shift threshold, the choice between them is irrelevant.
Solvent X is categorically unsafe for use on 18th-century paintings.
Solvent Y would likely be preferred as the default choice for routine use under the stated priorities.
Solvent X removes varnish quickly.
Explanation
This question tests the ability to make a valid inference from the passage. A correct inference must be logically supported by the information provided without being directly stated. The passage notes that Solvent Y removed varnish more slowly but left no residue, required no additional cleaning, and resulted in total treatment times that were shorter on average than Solvent X, which needed a time-consuming secondary step despite faster initial removal. Additionally, both solvents met the color-shift threshold, but Solvent X showed greater variability, and the priorities emphasize limited staff time and minimizing process complexity. Therefore, Solvent Y would likely be preferred as the default choice for routine use, as it better aligns with reducing overall time and complexity without compromising safety thresholds. A tempting incorrect choice, such as option B, states that Solvent X is categorically unsafe for 18th-century paintings, but this is too strong, as the passage indicates it met the threshold despite variability. Another option like E speculates that residues from Solvent X will inevitably cause long-term pigment loss in all cases, which exceeds the evidence of faint residues requiring secondary cleaning.
Read the passage and answer the question.
A political scientist studied the effects of open primary elections on candidate ideology in several states. In states that adopted open primaries, the average ideological score of winning candidates moved slightly toward the center over the next three election cycles. However, the shift was concentrated in competitive districts; in districts where one party routinely won by large margins, the average ideology of winners changed little. The researcher also found that turnout among self-identified independents rose modestly after open primaries were introduced, while turnout among strong partisans remained roughly stable. The study cautioned that district competitiveness can shape which voters campaigns prioritize.
The passage suggests which of the following?
After open primaries were adopted, independent turnout rose modestly while partisan turnout stayed roughly stable.
District competitiveness has no relationship to campaign strategy because primaries determine nominees, not general-election outcomes.
Open primaries always produce centrist winners regardless of local electoral conditions.
Open primaries caused strong partisans to stop voting in primary elections.
In competitive districts, candidates may have greater incentive to appeal to independents whose participation increased under open primaries.
Explanation
This question asks you to infer from the political science study on open primaries. Inferences must be supported by textual evidence rather than speculation. The passage indicates that ideological shifts toward the center were "concentrated in competitive districts" and that "district competitiveness can shape which voters campaigns prioritize." Combined with the finding that independent turnout rose under open primaries, this suggests candidates in competitive districts have more incentive to appeal to these newly participating independents. Option B correctly connects these pieces of evidence. Option C is too absolute ("always produce centrist winners"), while option E contradicts the passage's emphasis on competitiveness effects.
A team of ecologists investigated why a particular invasive plant spread rapidly along a river corridor but remained sparse in adjacent upland areas. They found that seeds of the plant were frequently present in river sediment samples after seasonal floods, and germination rates were high in moist, nutrient-rich soils typical of floodplains. In upland soils, germination was lower, and seedlings that did emerge showed higher mortality during dry periods. The ecologists also observed that most mature plants in the corridor were clustered near points where floodwaters deposited debris, suggesting repeated seed delivery. They propose that managing floodplain disturbances could limit the invasion’s expansion.
Which of the following can be inferred from the passage?
Because the plant is invasive, it must have been intentionally introduced by humans near the river.
Seeds were frequently present in river sediment samples after seasonal floods.
The invasive plant cannot survive in any upland environment under any circumstances.
Flood events likely contribute both to dispersal of seeds and to creation of favorable conditions for establishment along the river corridor.
Upland areas would show higher invasion levels if nutrient-rich soils were imported there, regardless of moisture conditions.
Explanation
This question tests the ability to make a valid inference from the passage. A correct inference must be logically supported by the information provided without being directly stated. The passage notes seeds were frequently in flood sediments, with high germination in moist, nutrient-rich floodplain soils, and mature plants clustered near flood debris points, while uplands had lower germination and higher seedling mortality in dry periods. Floods thus deliver seeds and create favorable moist, nutrient conditions. Therefore, flood events likely contribute both to dispersal of seeds and to creation of favorable conditions for establishment along the river corridor, explaining the rapid spread there versus uplands. A tempting incorrect choice, such as option A, claims the plant cannot survive in any upland environment, but this is too absolute, as some germination occurred despite higher mortality. Another option like D assumes human introduction near the river, which is speculative and not mentioned.
A botanist studying pollination in an alpine meadow compared seed set in a wildflower across two elevations. At lower elevation, the flower was visited by a diverse set of insects, including bees and flies, and seed set was high. At higher elevation, overall insect visitation was lower, but a single bumblebee species accounted for most visits; seed set remained moderate rather than collapsing. When the botanist experimentally excluded insects using mesh bags, seed set dropped sharply at both elevations. The botanist concludes that the flower depends on insect pollination but may rely on different pollinator assemblages across environments.
Which statement is most strongly supported by the information given?
If the dominant bumblebee species disappears, the flower will certainly go extinct across its entire range.
At lower elevation, the flower was visited by bees and flies.
The mesh bags increased seed set by protecting flowers from harsh alpine winds.
At high elevation, the flower likely experiences some functional compensation from the dominant bumblebee species despite reduced overall visitation.
The flower is fully self-pollinating at high elevation and therefore does not depend on insects there.
Explanation
This question tests the ability to make a valid inference from the passage. A correct inference must be logically supported by the information provided without being directly stated. The passage indicates high-elevation seed set remained moderate despite lower overall visitation, dominated by one bumblebee species, while exclusion dropped seed set sharply at both elevations, showing insect dependence. Diverse insects visited at low elevation with high seed set. Therefore, at high elevation, the flower likely experiences some functional compensation from the dominant bumblebee species despite reduced overall visitation, maintaining moderate reproduction. A tempting incorrect choice, such as option B, claims the flower is fully self-pollinating at high elevation, but this contradicts the sharp drop with exclusion. Another option like D speculates extinction if the bumblebee disappears, which is too extreme and not supported.
A political scientist studied how citizens evaluate policy proposals depending on the order in which information is presented. Participants read about a proposed housing policy along with two pieces of evidence: one from an academic study and one from an anecdotal news story. When the academic study was presented first, participants rated the proposal as more evidence-based, even when they later read the anecdote. When the anecdote was presented first, participants’ ratings were lower and did not fully rebound after reading the academic study. The scientist notes that both groups received the same information; only the sequence differed.
It can be reasonably concluded that:
Presenting rigorous evidence earlier can have a lasting influence on how subsequent information is interpreted.
The academic study was fabricated and therefore persuaded participants only through deception.
Information order has no effect on policy evaluation because both groups received the same content.
Participants read both an academic study and an anecdotal news story.
Participants who saw the anecdote first were unable to understand academic studies.
Explanation
This question tests the ability to make a valid inference from the passage. A correct inference must be logically supported by the information provided without being directly stated. The passage demonstrates that when the academic study was presented first, ratings of the policy as evidence-based remained higher even after the anecdote, while anecdote-first ratings were lower and did not fully rebound after the study. Both groups received the same information, differing only in sequence. Therefore, presenting rigorous evidence earlier can have a lasting influence on how subsequent information is interpreted, as the order affected final evaluations persistently. A tempting incorrect choice, such as option E, claims order has no effect because content was the same, but this ignores the observed differences in ratings. Another option like A speculates that anecdote-first participants were unable to understand studies, which is not supported and too dismissive.
In a study of urban heat mitigation, researchers compared three neighborhoods that installed different combinations of interventions over a five-year period. Neighborhood L replaced most dark asphalt with high-albedo pavement but did not increase tree canopy; Neighborhood T expanded tree canopy substantially but left pavement largely unchanged; Neighborhood M implemented both measures at moderate levels. The researchers reported that summertime afternoon surface temperatures decreased in all three neighborhoods relative to baseline. However, only Neighborhood T showed a consistent reduction in overnight air temperatures during heat waves, and residents there reported fewer sleep disruptions. The researchers also noted that high-albedo pavement produced the largest midday surface-temperature reductions but coincided with increased glare complaints and no measurable change in nighttime air temperature. In Neighborhood M, modest reductions occurred for both midday surface temperatures and overnight air temperatures, though neither matched the largest reductions observed in L (midday) or T (overnight). City officials are considering which single intervention to prioritize in other areas where the primary public-health concern is heat-wave mortality, which is most strongly associated with sustained elevated nighttime air temperatures rather than peak daytime surface temperatures.
Which of the following can be inferred from the passage?
High-albedo pavement is ineffective at reducing any type of heat exposure and should not be used in cities.
Because glare complaints increased, high-albedo pavement will likely be banned by the city in future projects.
Neighborhood M’s combined strategy proves that moderate implementation always outperforms intensive implementation of a single measure.
If officials must choose only one intervention to address heat-wave mortality risk, expanding tree canopy is the better-supported option.
All three neighborhoods experienced lower summertime afternoon surface temperatures than at baseline.
Explanation
This question tests the ability to make a valid inference from the passage. A correct inference must be logically supported by the information provided without being directly stated. The passage indicates that heat-wave mortality is most strongly associated with sustained elevated nighttime air temperatures, and only Neighborhood T, with expanded tree canopy, showed consistent reductions in overnight air temperatures during heat waves. In contrast, Neighborhood L's high-albedo pavement reduced daytime surface temperatures but did not affect nighttime air temperatures, while Neighborhood M's moderate approach yielded modest but not maximal reductions in either metric. Therefore, if officials must choose only one intervention to address heat-wave mortality risk, expanding tree canopy is the better-supported option, as it directly targets the key factor linked to mortality. A tempting incorrect choice, such as option A, claims high-albedo pavement is ineffective at reducing any type of heat exposure, but this is too absolute and ignores its stated effectiveness on daytime surface temperatures. Another option like E overgeneralizes Neighborhood M's results to claim moderate implementation always outperforms intensive single measures, which is speculative and not supported by the evidence.
In an archival analysis, a historian compared the budgeting practices of two early 20th-century municipal governments. City R published detailed annual budgets and held public hearings before final approval; City S published only summary totals and did not record deliberations in accessible minutes. Over a 15-year span, both cities experienced similar economic shocks, but City R showed smaller year-to-year fluctuations in infrastructure spending. The historian also found that in City S, major spending increases often followed election years, whereas City R’s spending increases were more evenly distributed. The historian cautions that publication practices do not automatically reveal motives but can affect how easily citizens and journalists scrutinize decisions.
Which statement is most strongly supported by the information given?
Because both cities experienced similar economic shocks, transparency has no relationship to spending patterns.
City R published detailed annual budgets and held public hearings.
City R’s greater budget transparency likely made sustained public scrutiny of spending decisions easier than in City S.
City S’s officials were more corrupt than City R’s officials.
City S would have had stable infrastructure spending if it had held public hearings, regardless of all other factors.
Explanation
This question tests the ability to make a valid inference from the passage. A correct inference must be logically supported by the information provided without being directly stated. The passage describes City R's detailed budgets and public hearings leading to smaller fluctuations in infrastructure spending, while City S's summary totals and inaccessible minutes correlated with larger, election-tied increases. The historian notes that publication practices affect scrutiny by citizens and journalists. Therefore, City R’s greater budget transparency likely made sustained public scrutiny of spending decisions easier than in City S, contributing to more stable patterns. A tempting incorrect choice, such as option A, assumes City S’s officials were more corrupt, but this is speculative and not supported by evidence. Another option like E overgeneralizes that public hearings alone would stabilize City S’s spending regardless of other factors, which is too absolute.
A journal editor examined citation patterns after introducing a double-blind peer-review policy (reviewers and authors anonymous to each other). In the three years before the change, papers from the journal’s host institution accounted for 18% of accepted articles; in the three years after, they accounted for 11%. Over the same periods, the proportion of submissions from the host institution remained approximately constant. The editor also noted that acceptance rates for papers from institutions with which editorial-board members had past collaborations declined slightly after the policy change. Which statement is most strongly supported by the information given?
Host-institution papers accounted for 11% of accepted articles in the three years after the change.
Papers from the host institution were of lower quality after the policy change.
The policy change likely reduced advantages previously associated with institutional proximity to the journal’s editors.
Double-blind review eliminated all forms of bias in the journal’s decisions.
After the policy change, authors from the host institution stopped submitting to the journal.
Explanation
This question tests inference about the effects of policy changes. Valid inferences must be supported by the passage without being explicitly stated. The data shows that host-institution papers dropped from 18% to 11% of acceptances after double-blind review was introduced, while submission proportions stayed constant. This suggests the previous system gave host-institution authors an advantage, likely due to reviewers knowing their institutional affiliation. The correct answer infers that double-blind review reduced this proximity advantage. Option E merely restates a fact from the passage rather than making an inference, while option A overgeneralizes beyond what the evidence supports.
Marine biologists assessed the recovery of a kelp forest after a severe storm. They monitored three sites: Site A was adjacent to a protected marine reserve with abundant sea otters; Site B had few otters due to historical hunting and ongoing boat traffic; Site C had intermediate otter presence. Over two years, kelp cover increased fastest at Site A and slowest at Site B. The researchers also counted sea urchins, which graze kelp: urchin densities remained low at Site A, increased at Site B, and fluctuated at Site C. The team noted that the storm initially reduced kelp at all sites to similarly low levels, suggesting comparable starting conditions.
Which of the following can be inferred from the passage?
Sea urchins at Site A must have been completely absent throughout the study.
Kelp cover increased fastest at Site A.
Sea otters likely contributed to kelp recovery by limiting sea urchin populations.
Because the storm affected all sites, predators cannot influence recovery rates afterward.
Boat traffic is the sole cause of kelp decline in all coastal ecosystems.
Explanation
This question tests the ability to make a valid inference from the passage. A correct inference must be logically supported by the information provided without being directly stated. The passage reports that kelp cover increased fastest at Site A with abundant sea otters, slowest at Site B with few otters, and intermediate at Site C, while sea urchin densities remained low at A, increased at B, and fluctuated at C. Sea otters are known predators of urchins, which graze kelp, and the storm reduced kelp similarly at all sites initially. Therefore, sea otters likely contributed to kelp recovery by limiting sea urchin populations, as the patterns align with otter presence correlating to lower urchins and faster kelp regrowth. A tempting incorrect choice, such as option B, claims boat traffic is the sole cause of kelp decline everywhere, but this is too absolute and ignores the role of predators. Another option like D speculates that urchins were completely absent at Site A, which is not stated and exceeds the evidence of low densities.
A chemist compared two catalysts for converting carbon dioxide into a useful chemical feedstock. Catalyst A achieved higher conversion efficiency in short laboratory runs but lost activity after repeated cycles, apparently due to surface restructuring. Catalyst B had lower initial efficiency but maintained stable activity across many cycles. When the chemist calculated total product generated over 100 cycles, Catalyst B yielded more cumulative product despite its lower per-run efficiency. The chemist notes that industrial processes often prioritize long-term throughput and stability over peak initial performance.
It can be reasonably concluded that:
Catalyst B’s stability proves that it cannot undergo any surface changes during reaction.
Catalyst A achieved higher conversion efficiency in short laboratory runs.
Catalyst B may be more suitable than Catalyst A for industrial deployment where repeated cycling is required.
Surface restructuring is always beneficial for catalyst performance.
Catalyst A will outperform Catalyst B in cumulative industrial output over long time horizons.
Explanation
This question tests the ability to make a valid inference from the passage. A correct inference must be logically supported by the information provided without being directly stated. The passage reports Catalyst A had higher initial efficiency but lost activity over cycles due to restructuring, while Catalyst B was stable with lower per-run efficiency but higher cumulative output over 100 cycles. Industrial processes prioritize long-term stability and throughput. Therefore, Catalyst B may be more suitable than Catalyst A for industrial deployment where repeated cycling is required, as its stability yields better overall performance. A tempting incorrect choice, such as option A, claims Catalyst A will outperform in cumulative output long-term, but this contradicts the 100-cycle calculation. Another option like E states surface restructuring is always beneficial, which ignores its role in A's activity loss.