All practice questions

For over half a century, Mayanist historiography was dominated by an ecological-collapse paradigm positing that unchecked population growth led to widespread deforestation, severe topsoil erosion, and the eventual catastrophic abandonment of Classic Maya urban centers. However, this narrative was fundamentally challenged when airborne Light Detection and Ranging (LiDAR) mapping revealed that vast swaths of the Maya Lowlands were covered by sophisticated networks of agricultural terracing and wetland canalization, demonstrating a far greater capacity for environmental engineering than previously assumed.

In response to these remote-sensing discoveries, an initial wave of revisionist scholars argued that these extensive landscape modifications represented a triumph of socio-ecological resilience. According to this view, terracing effectively trapped nutrient-rich sediments and conserved soil moisture, thereby neutralizing the threat of erosion and enabling continuous, high-yield agrarian production. The revisionist model thus framed the Classic Maya collapse not as an inevitable ecological disaster, but as an anomaly that must have stemmed from non-environmental factors such as geopolitical conflict or trade disruption.

More recently, however, high-resolution geoarchaeological soil core analysis has introduced a crucial qualification to this revisionist consensus. While confirming that terracing initially retarded sediment loss, these core samples indicate that the intensive construction and maintenance of terraces demanded immense, rigid labor commitments. When multi-decadal droughts struck the region during the terminal Classic period, this labor-intensive infrastructure became a vulnerability rather than a safeguard: as crop yields declined, communities could neither maintain the physical integrity of the terraces nor pivot to alternative subsistence strategies without incurring catastrophic social disruption.

Ultimately, the evolving scholarship suggests a more nuanced synthesis. Rather than viewing Maya terracing as either an ineffective defense against environmental degradation or an absolute guarantee of ecological resilience, modern researchers increasingly conceptualize it as a rigid technology that heightened systemic fragility. The collapse is thus best understood as a structural mismatch between a highly specialized, labor-intensive agrarian infrastructure and an unpredictable macro-climatic regime.

Which of the following best describes the overall rhetorical plan of the passage?

A logistics company uses two types of automated cargo drones, Drone X and Drone Y, to complete long-distance freight deliveries.

- Drone X travels at a constant speed of $40\text{ km/h}$ and consumes energy at a constant rate of $15\text{ kWh/h}$.
- Drone Y travels at a constant speed of $60\text{ km/h}$ and consumes energy at a constant rate of $25\text{ kWh/h}$.

On a completed joint mission, the two drones traveled a combined total distance of $480\text{ km}$ and consumed a combined total energy of $190\text{ kWh}$.

In the table below, select the number of hours that Drone X operated and the number of hours that Drone Y operated during this mission.

Which of the following correctly identifies the operating time, in hours, for Drone X and Drone Y, respectively?

An automated data processing pipeline evaluates five sequential stages ($k = 1, 2, 3, 4, 5$) to process machine learning workloads. At the start ($k = 0$), the system state is defined by Storage $S_0 = 10\text{ GB}$ and System Load $L_0 = 20\%$. At each subsequent stage $k$, the state vector $(S_k, L_k)$ updates according to the following rules:

- Stage 1 (Data Scrubbing): $S_1 = S_0 + 15$, $L_1 = L_0 + 10$
- Stage 2 (Feature Extraction): $S_2 = 2 \times S_1$, $L_2 = L_1 + 15$
- Stage 3 (Model Training): $S_3 = S_2 - 10$, $L_3 = L_2 + 25$
- Stage 4 (Batch Validation): $S_4 = S_3 + 20$, $L_4 = L_3 - 30$
- Stage 5 (System Deployment): $S_5 = S_4 - 25$, $L_5 = L_4 + 50$

The pipeline performance metric at any stage is defined as $M_k = S_k + L_k$.

Arrange the five stages in increasing order of their pipeline performance metric $M_k$ (from smallest value to largest value).

A regional health authority conducted a study across corporate workplaces to evaluate the impact of mandatory 15-minute guided mindfulness breaks introduced twice daily. Over a six-month trial, participating companies reported a 25% decrease in formal employee sick leave requests. Based on this outcome, the health authority concluded that the mindfulness breaks directly improved employee physical health and reduced illness incidence. Analysts and independent researchers provided four statements regarding these results.

Match each analytical statement with the precise logical role it plays in evaluating the health authority's causal argument.

Passage:
In evolutionary ecology, the phenomenon of "trophic decoupling latency" describes a systemic vulnerability that arises when an obligate predator species and its primary prey rely on different environmental cues to regulate their seasonal lifecycles. Typically, the predator species relies on photoperiodism—invariant photoperiod cues such as day length—to trigger its reproductive cycle, whereas the prey species responds directly to ambient thermal shifts to initiate breeding and emergence. During periods of rapid climatic warming, the prey species advances its lifecycle earlier in the spring, decoupling the timing of maximum prey availability from the peak nutritional demands of offspring predator rearing.

Crucially, the ecological impact of this temporal mismatch is not immediately apparent in overall predator abundance. Because adult predators possess sufficient metabolic resilience to survive the seasonal food deficit, adult mortality rates remain baseline in the short term, masking the underlying crisis. However, because newly hatched offspring suffer near-total mortality due to the absence of synchronized prey, recruitment into the breeding population halts entirely. Consequently, the predator population maintains a deceptive numerical stability for several years until the aging adult cohort reaches natural senescence, at which point the population experiences a sudden, irreversible collapse without prior warning signals.

Which of the following scenarios is most analogous to the phenomenon of "trophic decoupling latency" as described in the passage?

A telecommunications provider observed a 25% drop in subscriber churn in service areas where it concurrently upgraded its cell tower network to 5G and introduced a free device-protection plan for long-term contract holders. Company executives concluded that the speed improvements from the 5G upgrades were directly responsible for the reduction in subscriber churn. Which of the following statements, if true, provide valid logical evaluations that weaken the executives' causal conclusion? (Select all that apply.)

Until recently, ethnomusicologists and archivists studying acoustic oral traditions operated primarily under an archival paradigm that emphasized textualization—the systematic transcription of vocal performances into Western prescriptive notation and the storage of field recordings as static artifacts in central institutions. Proponents of this tradition argued that rigorous codification was essential to safeguard ephemeral musical repertoire from generational decay, particularly in indigenous communities experiencing rapid socio-linguistic shifts. However, critical theorists have increasingly challenged this framework, pointing out that Western notation fundamentally distorts oral traditions by imposing rigid metric grids and equal-temperament scales onto microtonal inflections and fluid, elastic rhythmic structures. Moreover, static archival preservation treats dynamic performance traditions as frozen artifacts, stripping songs of their localized social contexts and interactive performance dynamics.

In response to these acknowledged limitations, a modern school of contemporary researchers advocates for a "participatory digital repository" model. Rather than aiming for authoritative, definitive transcription, this approach utilizes interactive digital platforms where community practitioners dynamically annotate audio recordings, upload regional performance variants, and document contextual oral histories in real time. By shifting the locus of archival authority from academic curators to active community members, participatory repositories attempt to recreate the living transmission pathways characteristic of traditional oral cultures.

Yet, this dynamic model is not without its own significant structural vulnerabilities. Skeptics observe that digital participatory platforms often presuppose reliable technological infrastructure and widespread digital literacy—conditions that remain unevenly distributed across rural or economically marginalized regions. Furthermore, unmediated community contributions can lead to conflicting attribution claims over communal repertoire, creating legal friction when digitized assets cross into global commercial domains. Consequently, while participatory digital repositories successfully address the cultural inflexibility of traditional codification, they inadvertently introduce complex technological and governance dilemmas that require nuanced, hybrid management strategies.

Which of the following best describes the overall logical structure of the passage?

A chemical processing plant prepares a batch of solution by mixing two stock liquid compounds, Solution A and Solution B, to form an initial mixture with a total mass of $480\text{ kg}$. Solution A contains $25\%$ active compound by mass, and Solution B contains $5\%$ active compound by mass. Solution A and Solution B are combined in a mass ratio of $3:1$, respectively.

To satisfy export specifications, technicians must raise the active compound concentration of the entire mixture to $25\%$ by mass by adding a quantity of pure active compound. How many kilograms of pure active compound must be added to the $480\text{ kg}$ mixture?

An automated logistics drone starts an operation at Cycle $k = 0$ with an initial battery charge of $C_0 = 100\%$ and a payload mass of $P_0 = 40\text{ kg}$. At the end of each subsequent cycle $k$ (where $k = 1, 2, 3, 4$), the payload mass decreases by $8\text{ kg}$ according to $P_k = P_{k-1} - 8$, and the remaining battery charge updates according to the state transition rule $C_k = C_{k-1} - (5 + 0.2 P_{k-1})\%$. Match each operational cycle on the left with its exact state $(C_k, P_k)$ at the end of that cycle on the right.

A high-tech manufacturing firm produced a batch of $150$ electronic assemblies. Each assembly in the batch underwent standard quality testing by Inspector Alpha, Inspector Beta, or both. Exactly $90$ assemblies were tested by Inspector Alpha and $105$ assemblies were tested by Inspector Beta. What was the average (arithmetic mean) testing duration per assembly for the entire batch of $150$ assemblies?

(1) The average testing duration for assemblies tested only by Inspector Alpha was $12$ minutes, and the average testing duration for assemblies tested only by Inspector Beta was $18$ minutes.
(2) The average testing duration for assemblies tested by both Inspector Alpha and Inspector Beta was $25$ minutes.

Which of the following statements provides sufficient information to answer the question?

In 2025, a nationwide logistics firm installed AI-driven route optimization software across its entire delivery fleet to reduce fuel consumption per trip. Over the following year, fuel prices remained completely stable, and the average fuel consumed per delivery dropped by 15 percent. Paradoxically, the firm's total annual fuel expenditure for the fleet increased by more than 10 percent over the same period.

Which of the following, if true, most helps to resolve the apparent discrepancy described above?

An urban planning committee observed that metropolitan neighborhoods with a high density of public community gardens reported significantly lower rates of stress-related cardiovascular conditions among residents than did neighborhoods with few or no community gardens. The committee concluded that exposure to community gardens directly reduces stress levels, thereby reducing the incidence of cardiovascular conditions among urban residents. Which of the following, if true, most seriously weakens the argument?

From 2015 to 2025, solar power generation in Country X expanded rapidly, growing from supplying 5 percent of the nation's total electricity consumption to 20 percent. Over the same ten-year period, the average greenhouse gas emissions per megawatt-hour of electricity generated from non-solar sources decreased by 10 percent. Total electricity consumption in Country X increased by 50 percent between 2015 and 2025.

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

A major automotive assembly plant recently replaced its manual welding lines with automated robotic arms, resulting in a 30 percent decline in the total number of physical injuries reported by line workers over the following year. Paradoxically, during the exact same period, the average number of workdays lost per worker due to job-related injuries increased by nearly 40 percent, even though safety reporting standards, total workforce size, and overall operating hours remained unchanged.

Which of the following, if true, most helps to resolve the apparent paradox described above?

A local agricultural extension office recently advised fruit orchard owners to plant wildflower strips along the perimeter of their crop fields. The office reasoned that these wildflower strips would attract a larger population of wild bees, which in turn would increase pollination and boost overall fruit yields per acre.

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

A water utility company in a drought-prone city plans to install automated pressure-regulating valves across its subterranean pipe network. The utility argues that by dynamically reducing water pressure during low-usage overnight hours, it will significantly decrease the total volume of water lost through minor background pipe leaks across the city.

Which of the following, if true, provides the strongest support for the water utility company's argument?

Historically, municipal water utilities facing severe drought conditions have implemented tier-based pricing structures that dramatically increase per-gallon rates for high-volume consumers. Economists reasoned that raising the marginal cost of excess usage would compel households to reduce discretionary consumption, such as lawn irrigation. Recent empirical data, however, reveals that in municipalities where tier-based pricing was instituted alongside subsidies for water-efficient household appliances, overall water consumption decreased significantly less than in municipalities that implemented tier-based pricing alone. This disparity occurs because the financial savings produced by the subsidized appliances effectively buffer households against the higher marginal cost of discretionary water use. Therefore, a municipal policy intended to maximize water conservation by combining tier pricing with appliance subsidies will likely prove ineffective unless ________.

Which of the following most logically completes the passage?

For three positive integers $a$, $b$, and $c$, the greatest common divisor of any pair among them is $12$, and the least common multiple of all three integers is $5,040$. If $a = 60$, what is the minimum possible value of $b + c$?

A statement determining that a real variable $x$ satisfies the quadratic equation $x^2 - 5x + 6 = 0$ is sufficient to answer the Data Sufficiency question 'Is $x$ an integer?', but is insufficient to answer the Data Sufficiency question 'What is the value of $x$?'

Consider the following international aerospace guidelines: A private satellite operator is granted a commercial orbital license only if its collision-avoidance system passes an automated telemetry audit. Passing an automated telemetry audit requires maintaining an active propulsion unit capable of immediate de-orbiting maneuvers.

Based on these guidelines, evaluate the following statement:
"If a private satellite operator maintains an active propulsion unit capable of immediate de-orbiting maneuvers, that operator is guaranteed to be granted a commercial orbital license."