LSAC LSAC Certifications LSAT-TEST Questions & Answers

• Question 631:

  Medical researcher: As expected, records covering the last four years of ten major hospitals indicate that babies born prematurely were more likely to have low birth weights and to suffer from health problems than were babies not born prematurely. These records also indicate that mothers who had received adequate prenatal care were less likely to have low birth weight babies than were mothers who had received inadequate prenatal care. Adequate prenatal care, therefore, significantly decreases the risk of low birth weight babies.

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

  A. The hospital records indicate that many babies that are born with normal birth weights are born to mothers who had inadequate prenatal care.

  B. Mothers giving birth prematurely are routinely classified by hospitals as having received inadequate prenatal care when the record of that care is not available.

  C. The hospital records indicate that low birth weight babies were routinely classified as having been born prematurely.

  D. Some babies not born prematurely, whose mothers received adequate prenatal care, have low birth weights.

  E. Women who receive adequate prenatal care are less likely to give birth prematurely than are women who do not receive adequate prenatal care.

  Correct Answer: B

  We have to weaken the medical researcher's argument, so as usual we have to identify the components of the argument. The conclusion is that adequate prenatal care significantly decreases the risk of low birth weight babies. The evidence for this is that hospital records show that mothers who had received adequate prenatal care were less likely to have low birth weight babies. The medical researcher also tells us that records show that babies born prematurely were more likely to have low birth weights than on-time babies. This is a classic correlation = causation argument: the author cites a high correlation between inadequate prenatal care and low birth weight babies, and then concludes that one must have caused the other. In most cases the best way to weaken these arguments is to find an alternative explanation, or to find a situation where the two are not correlated (you see X, but you don't see Y).

• Question 632:

  Quasars ?celestial objects so far away that their light takes at least 500 million years to reach Earth ?have been seen since 1963. For anything that far away to appear from Earth the way quasars do, it would have to burn steadily at a rate that produces more light than 90 billion suns would produce. But nothing that burns at a rate that produces that much light could exist for more than about 100 million years.

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

  A. Instruments in use before 1963 were not sensitive enough to permit quasars to be seen.

  B. Light from quasars first began reaching Earth in 1963.

  C. Anything that, from Earth appears as bright as a quasar does must produce more light than would be produced by 90 billion suns.

  D. Nothing that is as far from Earth as quasars are can continue to exist for more than about 100 million years.

  E. No quasar that has ever been seen from Earth exists any longer.

  Correct Answer: E

  Here's a rare Inference question that's vulnerable to prephrasing: Quasars burn so hot that they can't last for more than 100 million years, but light from quasars takes at least 500 million years to get here. Quasars have only been seen since 1963, and so any quasar light that anyone on Earth has seen has to be at least 500 million years old, and so, as option [No quasar that has ever been...] points out, that quasar itself cannot exist any more. By the time its light hits us, it's been dead for at least 400 million years.

• Question 633:

  Critic: Most chorale preludes were written for the organ, and the greatest chorale preludes written for the organ were written by J. S. Bach. One of Bach's chorale preludes dramatizes one hymn's perspective on the year's end. This prelude is agonizing and fixed on the passing of the old year, with its dashed hopes and lost opportunities. It does not necessarily reveal Bach's own attitude toward the change of the year, but does reflect the tone of the hymn's text. People often think that artists create in order to express their own feelings. Some artists do. Master artists never do, and Bach was a master artist.

  If the critic's statements are true, then on the basis of them which one of the following CANNOT be true?

  A. Bach believed that the close of the year was not a time for optimism and joyous celebration.

  B. In composing music about a particular subject, Bach did not write the music in order to express his own attitude toward the subject.

  C. In compositions other than chorale preludes, Bach wrote music in order to express his feelings toward various subjects.

  D. Most of Bach's chorale preludes were written for instruments other than the organ.

  E. Most of the great chorale preludes were written for instruments other than the organ.

  Correct Answer: C

  This would be a good one to postpone, as some of the later questions were less involved than this one. The question stem asks you to find the choice that must be false, so the best approach is to read through the stimulus once but be prepared to check back with it when you consult the choices. (There's far too much detail to expect to be able to handle the choices without checking back.) As it turns out, the correct answer comes from the last few sentences. Master artists never create in order to express their own feelings. Bach is a master artist, so he never created works (chorale preludes or not) to express his feelings.

• Question 634:

  All too many weaklings are also cowards, and few cowards fail to be fools. Thus there must be at least one person who is both a weakling and a fool.

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

  A. All weasels are carnivores and no carnivores fail to be non-herbivores, so some weasels are non-herbivores.

  B. Few moralists have the courage to act according to the principles they profess, and few saints have the ability to articulate the principles by which they live, so it follows that few people can both act like saints and speak like moralists.

  C. Some painters are dancers, since some painters are musicians, and some musicians are dancers.

  D. If an act is virtuous, then it is autonomous, for acts are not virtuous unless they are free, and acts are not free unless they are autonomous.

  E. A majority of the voting population favors a total ban, but no one who favors a total ban is opposed to stiffer tariffs, so at least one voter is not opposed to stiffer tariffs.

  Correct Answer: C

  The "All too many" is just literary, not logical, in nature. The first clause simply means Many or Some weaklings are cowards. The second clause can be read as Many or Most or Some cowards are fools. (Why are we seemingly being so loose in our translations? Because the choices are. Because whichever one of these turns out to be correct, it represents a significant verbal variation on the original. None of the choices reads "All too many X," or "few Y are not Z." So we have to stay a little flexible here.) With that in mind, a loose translation of the first clause would be: Some (or Most) of A are B, and the second as Some (or Most) B are C. When we turn to the conclusion, however, we can feel confident that it can be solidly translated. We know from our formal logic training that the phrase "At least one" means precisely one thing: SOME. So the conclusion is: Some weaklings are fools. Now, given that conclusion, we ought probably to be drawn first to options [All weasels are carnivores and no...], [Some painters are dancers, since...] and [A majority of the...], each of whose conclusions uses the word "Some" or the phrase "At least one." Let's start with those three.

• Question 635:

  Amphibian populations are declining in numbers worldwide. Not coincidentally, the earth's ozone layer has been continuously depleted throughout the last 50 years. Atmospheric ozone blocks UV-B, a type of ultraviolet radiation that is continuously produced by the sun, and which can damage genes. Because amphibians lack hair, hide, or feathers to shield them, they are particularly vulnerable to UV-B radiation. In addition, their gelatinous eggs lack the protection of leathery or hard shells. Thus, the primary cause of the declining amphibian population is the depletion of the ozone layer.

  Each of the following, if true, would strengthen the argument EXCEPT:

  A. Of the various types of radiation blocked by atmospheric ozone, UV-B is the only type that can damage genes.

  B. Amphibian populations are declining far more rapidly than are the populations of non-amphibian species whose tissues and eggs have more natural protection from UV-B.

  C. Atmospheric ozone has been significantly depleted above all the areas of the world in which amphibian populations are declining.

  D. The natural habitat of amphibians has not become smaller over the past century.

  E. Amphibian populations have declined continuously for the last 50 years.

  Correct Answer: A

  The question stem says that all of the answer choices would strengthen the argument EXCEPT the correct one. Therefore, the correct answer choice will either weaken the argument or have no effect at all. The conclusion of this argument is helpfully introduced by the Keyword "Thus": the primary cause of the declining amphibian population is the depletion of the ozone layer. The evidence is that populations have been declining at the same time the ozone layer has been depleted. Additionally, the ozone protects against UVB radiation, which can damage the genes of amphibians, who have no natural shields against the radiation. Option [Of the various types of radiation blocked by...], which suggests that no other type of ozone-blocked radiation damages genes, would strengthen the notion that UV-B is the primary cause of the declining amphibian population. After all, it rules out other causes. But that isn't the conclusion here. The author's conclusion is that ozone depletion is the primary cause of the declining amphibian population. That conclusion is unaffected by option [Of the various types of radiation blocked by...]. Whether the ozone caused damage to amphibian genes comes from one type of radiation or many doesn't matter to the author. He's only trying to show that it's ozone depletion and not something else.

• Question 636:

  In the decade from the mid-1980s to the mid-1990s, large corporations were rocked by mergers, reengineering, and downsizing. These events significantly undermined employees' job security. Surprisingly, however, employees' perception of their own job security hardly changed over that period. Fifty-eight percent of employees surveyed in 1984 and 55 percent surveyed in 1994 stated that their own jobs were very secure.

  Each of the following contributes to an explanation of the surprising survey results described above EXCEPT:

  A. A large number of the people in both surveys work in small companies that were not affected by mergers, reengineering, and downsizing.

  B. Employees who feel secure in their jobs tend to think that the jobs of others are secure.

  C. The corporate downsizing that took place during this period had been widely anticipated for several years before the mid-1980s.

  D. Most of the major downsizing during this period was completed within a year after the first survey.

  E. In the mid-1990s, people were generally more optimistic about their lives, even in the face of hardship, than they were a decade before.

  Correct Answer: B

  The question stem tells us that we're looking to explain surprising survey results. This just means that we have to resolve the paradox. So you should have first identified the paradox: even though massive downsizing occurred from the mid 1980s to the mid 1990s, which the author tells us undermined employees' job security, results from surveys taken in 1984 and 1994 asking employees about their job security were surprisingly similar. The reason this is surprising is that we would expect the workers in 1994 to feel much less secure, having experienced so many mergers, layoffs, etc. All of the incorrect answer choices will help to explain how the results could be similar. The one that doesn't is option [Employees who feel secure in their jobs...]. How the employees feel about the jobs of others is irrelevant. The argument concerns one's confidence in one's own job security.

• Question 637:

  All actions are motivated by self-interest, since any action that is apparently altruistic can be described in terms of self-interest. For example, helping someone can be described in terms of self-interest: the motivation is hope for a reward or other personal benefit to be bestowed as a result of the helping action.

  Which one of the following most accurately describes an error in the argument's reasoning?

  A. The term "self-interest" is allowed to shift in meaning over the course of the argument.

  B. The argument takes evidence showing merely that its conclusion could be true to constitute evidence showing that the conclusion is in fact true.

  C. The argument does not explain what is meant by "reward" and "personal benefit."

  D. The argument ignores the possibility that what is taken to be necessary for a certain interest to be a motivation actually suffices to show that that interest is a motivation.

  E. The argument depends for its appeal only on the emotional content of the example cited

  Correct Answer: B

  Getting the right answer to this question requires you to spot a scope shift. The author concludes that all actions are motivated by self-interest. Why? Because any action that is apparently altruistic can be described in terms of self-interest. As additional support, the author then gives an example of an altruistic act, and proceeds to describe it in terms of self-interest. Do you see how this is a subtle scope shift? The author is using evidence of how an action might be described to support a conclusion of what is actually motivating the action. These two things are not identical. Option [The argument takes evidence showing merely that...] gets at this discrepancy. Just because it could be true that helping someone was motivated by self-interest, (in other words, you could describe it that way) doesn't mean that it is in fact true that the action was motivated by self-interest.

• Question 638:

  Studies of the reliability of eyewitness identifications show little correlation between the accuracy of a witness's account and the confidence the witness has in the account. Certain factors can increase or undermine a witness's confidence without altering the accuracy of the identification. Therefore, police officers are advised to disallow suspect lineups in which witnesses can hear one another identifying suspects.

  Which one of the following is a principle underlying the advice given to police officers?

  A. The confidence people have in what they remember having seen is affected by their awareness of what other people claim to have seen.

  B. Unless an eyewitness is confronted with more than one suspect at a time, the accuracy of his or her statements cannot be trusted.

  C. If several eyewitnesses all identify the same suspect in a lineup, it is more likely that the suspect committed the crime than if only one eyewitness identifies the suspect.

  D. Police officers are more interested in the confidence witnesses have when testifying than in the accuracy of that testimony.

  E. The accuracy of an eyewitness account is doubtful if the eyewitness contradicts what other eyewitnesses claim to have seen.

  Correct Answer: A

  The question stem tells us to identify the principle behind the advice given to police officers. So what's the advice? It's signaled by the Keyword "therefore": cops are told not to trust identifications made when witnesses can hear one another. The rest of the stimulus explains why not. There's no connection between confidence and accuracy when it comes to identification, and some factors increase confidence without increasing accuracy. So we can understand why police officers would want to avoid these factors. Based on this information, police officers are advised to disallow identifications in which witnesses can hear one another, and so witnesses being able to hear each other must be one of those factors that increase confidence without increasing accuracy. So option [The confidence people have in what they remember...] is the principle lying behind the advice police officers receive.

• Question 639:

  Franklin: It is inconsistent to pay sports celebrities ten times what Nobel laureates are paid. Both have rare talents and work hard. Tomeka: What you've neglected to consider is that unlike Nobel laureates, sports celebrities earn millions of dollars for their employers in the form of gate receipts and TV rights.

  Franklin's and Tomeka's statements provide the most support for holding that they disagree about the truth of which one of the following?

  A. Nobel laureates should be taken more seriously.

  B. Nobel laureates should be paid more than sports celebrities.

  C. Sports celebrities and Nobel laureates work equally hard for their employers.

  D. There is no rational basis for the salary difference between sports celebrities and Nobel laureates.

  E. The social contributions made by sports celebrities should be greater than they currently are.

  Correct Answer: D

  The stem tells us to find the point at issue here. Franklin says that it doesn't make sense to pay sports celebrities more than Nobel laureates. Tomeka points out a relevant distinction: sports stars earn lots of cash for their employers in ways that laureates can't. So Tomeka suggests a line of reasoning for paying the sports stars more, whereas Franklin says there is no rational basis for doing so.

• Question 640:

  Ambiguity inspires interpretation. The saying "We are the measure of all things," for instance, has been interpreted by some people to imply that humans are centrally important in the universe, while others have interpreted it to mean simply that, since all knowledge is human knowledge, humans must rely on themselves to find the truth.

  The claim that ambiguity inspires interpretation figures in the argument in which one of the following ways?

  A. It is used to support the argument's conclusion.

  B. It is an illustration of the claim that we are the measure of all things.

  C. It is compatible with either accepting or rejecting the argument's conclusion.

  D. It is a view that other statements in the argument are intended to support.

  E. It sets out a difficulty the argument is intended to solve.

  Correct Answer: D

  The phrase mentioned in the question stem (ambiguity inspires interpretation) is the very first line of the stimulus. So what role does it play? There's only one more sentence to the stimulus, and it's an extended example, signaled by the evidence Keyword phrase "for instance." So the phrase "ambiguity inspires interpretation" is the conclusion, supported by the example of the differing interpretations of the phrase "we are the measure of all things."