All practice questions

In an attempt to reduce employee burnout and decrease staff turnover, a large accounting firm transitioned all its employees from a standard five-day workweek to a four-day workweek, keeping their annual salaries unchanged. Surprisingly, one year after this policy was implemented, employee surveys showed a significant increase in reported burnout, and the firm's staff turnover rate was higher than it had been in the previous five years. Which of the following, if true, most helps to resolve the apparent discrepancy in the information above?

The Negation Technique is a critical tool for evaluating Necessary Assumptions on the LSAT. Match each candidate assumption statement on the left with its logically precise negation on the right.

Match each flawed argument stimulus to the abstract description that most accurately identifies its logical error.

Agricultural researcher: A newly engineered strain of wheat produces a compound toxic to the wheat midge. In recent trials, plots planted with the engineered strain suffered 85 percent less midge damage than plots planted with conventional wheat. Since the engineered strain costs exactly the same to cultivate per acre as conventional wheat, replacing conventional wheat with the engineered strain across the agricultural sector will definitively result in a substantial increase in overall agricultural profitability.

Which one of the following is an assumption on which the agricultural researcher's argument depends?

Archaeologist: At the ancient site of Keltis, sophisticated wheel-thrown pottery completely replaces older, hand-built styles in excavation layers dating from 1200 BCE onward. Some scholars argue this sudden shift indicates that Keltis was conquered and repopulated by a foreign empire. However, chemical analysis confirms that the wheel-thrown pieces were made from the exact same local clay pits used for the earlier hand-built pieces. Therefore, the original inhabitants of Keltis must have independently invented the potter's wheel.

Which one of the following is an assumption on which the archaeologist's argument depends?

Sociologist: Sustaining rapid economic growth requires a society to foster a culture of widespread technological innovation. However, a society will fail to cultivate such a culture if it does not possess a robust and accessible educational system. Observers note that several developing nations are currently investing heavily to overhaul and expand their educational infrastructure. Therefore, it is inevitable that these nations will soon experience sustained rapid economic growth.

Which of the following most accurately describes a flaw in the sociologist's reasoning?

Sociologist: Most of the residents in this neighborhood commute by train. Furthermore, most of the residents in this neighborhood regularly vote in local elections. Consequently, it must be the case that most of the residents in this neighborhood who commute by train regularly vote in local elections.

The flawed pattern of reasoning in the sociologist's argument is most closely paralleled by which one of the following?

Philosopher of Science: For a theoretical framework to be deemed scientifically mature, its core postulates must yield observable consequences that can be strictly isolated from confounding variables. The newly proposed String-Loop synthesis yields observable consequences only at energy scales present in the early universe, where isolating variables from cosmic background fluctuations is fundamentally impossible. Therefore, the String-Loop synthesis cannot be utilized as a foundational text in graduate-level physics curricula.

Which one of the following is an assumption required by the philosopher of science's argument?

Analyze the reasoning in each of the following short arguments. Pair each argument with the abstract description that most accurately identifies its primary logical vulnerability.

Read the following argument and evaluate the statement below it.

Archaeologist: Historical records show that whenever an ancient empire rapidly expanded its territory, it subsequently suffered a severe economic depression due to overextended supply lines. Recent analysis of the ancient Valerian Empire reveals that it suffered a catastrophic economic depression in its final decades. Therefore, the Valerian Empire must have rapidly expanded its territory shortly before its fall.

Statement: The archaeologist's argument is vulnerable to criticism because it draws a broad conclusion about ancient empires based on a single, potentially unrepresentative historical example.

Professor Aris: We should temporarily suspend the use of ground-penetrating radar at the Highland Valley burial site until the new, non-invasive imaging algorithms are fully calibrated next year. If we proceed now with our current, outdated technology, the resulting data could be misinterpreted, potentially leading to unnecessary excavation that irrevocably damages the fragile topsoil structure.

Dr. Vance: Your suggestion that we completely abandon technological assistance in archaeological surveys is absurd. Without any modern imaging tools, our field would regress to the nineteenth century, relying solely on random digging and guesswork, which would ultimately destroy far more historical sites than it preserves.

Which one of the following most accurately describes a flaw in Dr. Vance's reasoning?

Researcher: The hormone somatotropin stimulates growth in juvenile *Rana clamitans*. In a strictly controlled laboratory study, two groups of these frogs were observed for six months. Both groups were provided with identical diets and environmental conditions, differing only in the water's dissolved calcium concentration. The frogs in the high-calcium water exhibited growth rates 30 percent higher than those in the low-calcium water. Because both groups of frogs synthesized identical amounts of somatotropin over the study period, the dissolved calcium must directly enhance the sensitivity of the frogs' cellular growth receptors to this hormone.

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

Epidemiologist: Proponents of the new hospital sanitation directive claim that it significantly reduces the rate of nosocomial (hospital-acquired) infections. They support this by pointing out that in the two years since the directive was issued at General Hospital, the number of nursing staff fully complying with the directive has steadily risen, which has in turn fostered a culture of heightened hygiene awareness. But the proponents' claim is entirely misguided. Over that exact same two-year period, the overall rate of nosocomial infections at General Hospital actually increased by 12 percent.

The epidemiologist's argument is most vulnerable to criticism on the grounds that it...

Match each flawed argument (which lacks a necessary premise to be logically valid) with the sufficient assumption that, if added to the premises, would allow its conclusion to be properly drawn.

Marine Biologist: The rapid proliferation of the spiny sea urchin is devastating our region's kelp forests. To prevent the complete loss of these forests, conservationists plan to introduce the sunflower sea star, a natural predator of the urchin. Because the sunflower sea star actively hunts these urchins and does not consume kelp, this introduction will successfully halt the destruction of the kelp forests.

Statement: The marine biologist's argument logically depends on the assumption that introducing the sunflower sea star will eliminate the spiny sea urchin population entirely.

All botanists possess a deep understanding of plant biology. Some participants at the current conference are botanists. Therefore, some participants at the current conference possess a deep understanding of plant biology.

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

Epidemiologist: Our study found that residents of County X who regularly consumed dietary supplements were 30% less likely to develop sleep disorders than those who did not. However, the supplement consumers also reported exercising significantly more on average. Since regular exercise is known to improve sleep quality, we conclude that the supplements themselves likely provide no real protection against sleep disorders.

Evaluate the following statement:
The epidemiologist's argument necessarily assumes that the dietary supplements consumed in County X do not contain ingredients that completely counteract the sleep-enhancing benefits of regular exercise.

Below are four distinct arguments that rely on unstated conditional rules. Pair each argument with the corresponding overarching principle that conclusively bridges the gap between its premises and its conclusion.

Cardiologist: In a recent clinical trial, patients with mild hypertension who took a daily dose of compound X experienced a 10 percent greater reduction in blood pressure than patients who received a placebo. Compound X has virtually no side effects, whereas conventional blood pressure medications often cause persistent fatigue and dizziness. Therefore, to minimize patient discomfort while effectively managing their condition, doctors should prescribe compound X instead of conventional medications for patients with mild hypertension.

Which of the following would be most useful to know in order to evaluate the cardiologist's argument?

Match each of the following argumentative scenarios with the universal principle that, if assumed to be valid, most strongly justifies its conclusion.