LSAT Prep Test 81 - Logical Reasoning 1 – Questions + Answers

For the first few weeks after birth, the dunnart has such poor control over its respiratory muscles that it cannot use them to breathe. Instead, this tiny marsupial breathes through its thin skin, which gradually thickens as the dunnart matures inside its mother’s pouch. The dunnart is unique among warm-blooded animals, the rest of which need thick skin throughout their lives to maintain body temperature and reduce water loss.

Which one of the following, if true, most helps explain how newborn dunnarts manage to survive despite their thin skins?

Successful stand-up comedians are able to keep the attention of a large audience for a few hours, in such a way that the audience remembers long afterwards what the comedian said. And in their routines, many comedians make interesting points about serious topics. Unsurprisingly, humor is the means through which comedians are able to accomplish all of this. University professors hope to achieve much the same in their lectures. Thus, .

Which one of the following most logically completes the argument?

Reviewer: Almost all books that offer management advice are written from the perspective of the CEO. But most managers aren’t CEOs and don’t have the same perspective as CEOs. So the advice in management books is of limited use for most managers.

The conclusion of the reviewer’s argument can be properly drawn if which one of the following is assumed?

The mayor has been accused of taking a bribe based on the fact that a consultant that does business with the city paid for improvements to the mayor’s vacation house. In his own defense, the mayor has said that he paid every bill for those improvements that was presented to him.

Which one of the following, if true, most undermines the mayor’s defense?

Archaeologist: The earliest evidence of controlled fire use in Europe dates to just 400,000 years ago. This casts doubt on the commonly held view that, because of Europe’s cold winter climate, mastery of fire was a necessary prerequisite for humans’ migration there.

Which one of the following is an assumption required by the argument?

Astronomer: This country’s space agency is currently building a new space telescope that is, unfortunately, way over budget. Some people argue that the project should be canceled. But that would be a mistake. If we cancel it now, all the money that has already been is spent—which more than the additional cost required to complete the be wasted.

project—would Which one of the following principles, if valid, would most help to justify the astronomer’s argument?

Naturalist: Different nonhuman primate species exhibit many contrasts in behavior. If a zookeeper leaves a screwdriver within reach of a chimpanzee, the animal is likely to examine and play with it for a time, and then move on to something else. In the same circumstances, an orangutan is likely to pretend to ignore the tool at first; later, in the zookeeper’s absence, the orangutan may use the screwdriver to try to dismantle its cage.

Which one of the following is most strongly supported by the naturalist’s statements?

Manager: The only employees who should receive bonuses this year are those who were exceptionally productive over the past year. Liang is an excellent account executive, but she works in a corporate division that has failed to meet its productivity goals for the year. Thus Liang should not receive a bonus this year.

The reasoning in the manager’s argument is flawed in that the argument

Even though she thought the informant was untrustworthy, the journalist promised not to reveal his identity so long as the information he provided did not turn out to be false. However, she will publicly reveal the informant’s identity if she is ordered to do so by a judge or her editor. After all, the information concerns safety violations at the power plant. Thus, the journalist will surely reveal the informant’s identity even if the information is accurate.

The conclusion of the argument follows logically if which one of the following is assumed?

One who has borrowed an item from someone and promised to return it by a certain date should do so if it would not be difficult to return it on time and the person from whom one has borrowed it has not given permission to return the item late.

The principle stated above most helps to justify the reasoning in which one of the following arguments?

Human skin gives off an array of gaseous substances, including carbon dioxide and lactic acid, both of which attract mosquitoes. However, neither of these two substances, whether alone or combined with one another, will attract mosquitoes as much as a bare human arm will, even in complete darkness, where a mosquito has no visual cues. Therefore, some other gaseous substance given off by human skin also attracts mosquitoes.

The reasoning in the argument requires which one of the following assumptions?

A 1955 analysis of paint samples from an Italian painting found evidence of cobalt, suggesting the use of cobalt blue, a pigment not used in Europe before 1804. The painting was thus deemed to have been produced sometime after 1804. A 2009 analysis also found cobalt, but that analysis suggested that the painting might have been produced before 1804.

Which one of the following, if true, most helps to resolve the apparent discrepancy in the information above?

A six-month public health campaign sought to limit the spread of influenza by encouraging people to take precautions such as washing their hands frequently and avoiding public places when they experience influenza symptoms. Since the incidence of influenza was much lower during those months than experts had predicted, the public evidently heeded the campaign.

Which one of the following, if true, most strengthens the argument?

A study at a company found that most meetings showed diminishing returns after 30 minutes, and little could be expected after 60 minutes. Moreover, the most productive meetings were those for which a clear time frame was established. For a meeting at the company to achieve maximum productivity, then, it needs to have a clear time frame and be no more than 30 minutes long.

Which one of the following most accurately expresses the conclusion drawn in the argument?

Nutritionist: Most fad diets prescribe a single narrow range of nutrients for everyone. But because different foods contain nutrients that are helpful for treating or preventing different health problems, dietary needs vary widely from person to person. However, everyone should eat plenty of fruits and vegetables, which protect against a wide range of health problems.

Which one of the following is most strongly supported by the nutritionist’s statements?

The caffeine in coffee stimulates the production of irritating acid in the stomach. But darker roasts of coffee, produced by roasting the coffee beans longer, contain more N-methylpyridinium (NMP) than lighter roasts, and NMP tends to suppress production of acid in the stomach. Therefore if you drink caffeinated coffee, darker roasts will irritate your stomach less than lighter roasts.

The answer to which one of the following questions most helps in evaluating the argument?

Film historians often find it difficult to determine typical audience members’ responses to particular films, especially those from the early twentieth century. Box office figures help little, for they indicate only a film’s financial success or failure; they do not show what audiences found funny, or frightening, or moving. These historians also find that newspaper and magazine reviews fail to provide much insight.

Which one of the following is most strongly supported by the statements above?

The consensus among astronomers, based upon observations of the surfaces of pulsars, is that pulsars are spinning balls of neutrons compressed into a sphere some 10 kilometers in diameter with a mass roughly equal to that of our sun. However, their observed properties are also consistent with some pulsars actually being filled with quarks, the building blocks of neutrons. Because the core of a quark-filled pulsar, unlike a neutron-filled one, would have an overall positive charge, it would attract a layer of negatively charged particles that could support a crust of neutrons.

The statement that the core of a quark-filled pulsar would have an overall positive charge plays which one of the following roles in the argument above?

Analyst: Any new natural-gas-powered electrical generation station needs to be located close to a natural-gas pipeline, a large body of water for cooling, and transmission lines. It also must be situated in a region where residents will not oppose construction. Our country has an extensive system of transmission lines, but our natural-gas pipelines run in the vicinity of only three of our large bodies of water, and residents would oppose any significant construction projects near these bodies of water.

The analyst’s statements, if true, most strongly support which one of the following statements about the analyst’s country?

Voting records regularly show that people over 65 vote in the highest percentages while young adults are least likely to vote. This indicates that citizens are becoming increasingly disconnected from the political system with each passing generation.

The argument’s reasoning is questionable in that the argument

A local marsh would need to be drained before the proposed office complex could be built. Such marshes often play crucial roles in purifying groundwater and there has been no scientific assessment of the marsh’s role in maintaining the quality of the city’s well water. The city should therefore block the proposed office complex pending such an assessment.

The principle underlying the argument above is most similar to the principle underlying which one of the following arguments?

In a recent study, one group of participants watched video recordings of themselves running on treadmills, and a second group watched recordings of other people running on treadmills. When contacted later, participants in the first group reported exercising, on average, 1 hour longer each day than did the other participants. This shows that watching a recording of yourself exercising can motivate you to exercise more.

Which one of the following, if true, most weakens the argument?

Environmentalist: Efforts to attain an overall reduction in carbon use by convincing people to focus on their personal use of fossil fuels cannot achieve that goal. Even if most people changed their behavior, changes in personal use of fossil fuels cannot produce the needed reductions in carbon use. Only government policies can produce change on the required scale.

The environmentalist’s argument requires assuming which one of the following?

There are only two plausible views about where the aesthetic value of a painting lies: either in its purely formal qualities or in what the painting means. But there exists no compelling general account of how a painting coilld derive its value from its purely formal characteristics. Therefore, the aesthetic value of a painting lies in what it means.

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

Substantial economic growth must be preceded by technological innovations that expanding industries incorporate into their production or distribution procedures. Since a worldwide ban on the use of fossil fuels would surely produce many technological innovations, it is obvious that such a ban would be followed by an economic boom rather than by the economic depression forecast by the critics of such a ban.

Which one of the following most accurately describes a flaw in the argument’s reasoning?

Winston: The rules for awarding Nobel Prizes stipulate that no more than three people can share the same prize. Nobel Prizes in scientific disciplines are generally given in recognition of particular scientific results, however, and many important results are the work of four or more scientists. Sanjay: Those rules also stipulate that prize winners must be living, but some highly influential scientists died before their work was fully appreciated.

The dialogue most strongly supports the claim that Winston and Sanjay agree that