Anna: But the videocassette itself only accounts for 5 percent of the price a video rental store pays to buy a copy of a movie on video; most of the price consists of royalties the store pays to the studio that produced the movie. So the price that video rental stores pay per copy would decrease by considerably less than 5 percent, and royalties would have to be paid on additional copies.
Summarize Argument
Without stating her conclusion directly, Anna argues that switching to the new videocassette will not save rental stores much money. Why? Because the actual videocassette costs little compared to royalties, and buying copies of movies more frequently would require the stores to pay those royalties more often.
Notable Assumptions
Anna assumes the new videocassette will not lead to a large increase in rentals. In addition, she assumes that rental stores routinely wear out videocassettes, or would do so if they switch to the new kind. She also assumes that a savings of far less than five percent is not “significantly more economical” than no savings, and that the royalties paid more often would be paid at a similar price.
A
The price that video rental stores pay for movies recorded on videocassettes is considerably less than the retail price of those movies.
This explains how the stores remain in business, not why switching to the new videocassette would save them money. If stores pay a small amount for videocassettes to begin with, then Tony’s position is more challenging to defend.
B
A significant proportion of the movies on videocassette purchased by video rental stores are bought as replacements for worn-out copies of movies the stores already have in stock.
This doesn’t imply the stores would avoid paying royalties on those purchases. It’s possible a store pays royalties each time it purchases a new videocassette, in which case this fact would not save rental stores money.
C
The royalty fee included in the price that video rental stores pay for movies on the new kind of videocassette will be half that included in the price of movies on the old kind.
This weakens Anna’s argument by questioning her assumption that the new videocassette would only save stores money on the physical copies. If stores will also save on royalty costs, their total savings may be much greater than 5 percent.
D
Given a choice, customers are more likely to buy a movie on videocassette than to rent it if the rental fee is more than half of the purchase price.
Since it is unknown how rental fees and purchase prices compare, this information is useless. It cannot be applied to video rental stores in total.
E
Many of the movies rented from video rental stores, particularly children’s movies, average several viewings per rental fee.
This may explain why the videocassettes get worn out, but does not support either speaker’s argument. Neither Anna nor Tony relies on the rate that videocassettes need replaced for their argument.
Okay so the stimulus is telling us about some psychological studies, where subjects were told to read something and that whatever it was they read caused them to develop some beliefs. Then, the researchers told them that the statements they had read were false. Counterintuitively most of the people who had formed these beliefs stuck with them, even after being told that the statements that led to them were false. This is the phenomenon that is seeking an explanation, and the journal proposes that this is because once humans acquire a belief they tend to hold on to that belief.
We have the weaken this argument, so we are really looking for another reason why these people might have stuck to their original belief that is not the result of some innate tendency to maintain ones beliefs.
Answer choice (A) really does not tell us anything. Whether the beliefs were correct or not is irrelevant to the point at issue. We are wondering why these people continued to believe they were correct even when told the opposite.
Answer choice (B) is really more an opinion than anything else. Who cares if it's unrealistic?
Answer choice (C) is similar, who cares if the statements were misleading. The participants formed beliefs, those beliefs were then challenged, and the participants maintained them nevertheless. Whether the original basis for those beliefs was actually misleading is irrelevant.
Answer choice (D) is the correct answer. If the subjects had acquired confirmation of the beliefs before being told the original statements were false, they would not need the original statements to maintain the belief. There would be another support structure for the beliefs that they developed and the original statements could fall away without a problem.
Answer choice (E) again is just totally irrelevant. Their skepticism does not actually matter because we are told that they did in fact form beliefs.
Summarize Argument: Phenomenon-Hypothesis
The journal concludes that people retain their acquired beliefs even when they are no longer supported. It points to studies where people formed beliefs on the basis of information, then kept those beliefs after learning the information was inaccurate.
Notable Assumptions
The journal assumes that the inaccurate information provided to participants was the only credible evidence to support their beliefs. It also assumes subjects were convinced that the original information was false, or at least given good reason to believe so.
A
Regardless of the truth of what the subjects were later told, the beliefs based on the original statements were, for the most part, correct.
It isn’t relevant whether their beliefs were correct, only whether there was credible evidence to support them. If the subjects held their beliefs despite lacking evidence for them, the argument stands even if those beliefs were true.
B
It is unrealistic to expect people to keep track of the original basis of their beliefs, and to revise a belief when its original basis is undercut.
This suggests it’s unrealistic to expect the opposite outcome, but does not challenge the conclusion drawn. It’s another possible conclusion of the argument, more strongly supported than the actual conclusion.
C
The statements originally given to the subjects would be highly misleading even if true.
It isn’t relevant that the information was inaccurate or misleading, only that participants first believed it and subsequently learned it was false. This doesn’t say the subjects were aware the statements were false or misleading.
D
Most of the subjects had acquired confirmation of their newly acquired beliefs by the time they were told that the original statements were false.
This suggests subjects held their beliefs based on other credible information. Though their original basis was debunked, they had other evidence supporting their new beliefs.
E
Most of the subjects were initially skeptical of the statements originally given to them.
This doesn’t change the fact that subjects developed new beliefs based on that information, then refused to change them upon learning that information was false. It makes their behavior more surprising, but does not challenge the argument.
Summary
Zoos are both educational and entertaining. However, removing animals from their natural habitats to populate the earliest zoos caused some species’ populations to reduce and endangered their survival. Today, most new zoo animals are bred from captive breeding programs. These programs make possible efforts to restore populations of endangered species in the wild.
Strongly Supported Conclusions
At least some animals bred through captive breeding programs are of an endangered species.
A
Zoos have played an essential role in educating the public about endangered species.
We don’t know whether zoos have played an essential role or not. We only know that zoos have served as an educational resource. Additionally, we don’t know whether these educational resources were specific to endangered species.
B
Some specimens of endangered species are born and bred in zoos.
If captive breeding programs make reestablishing endangered species in the wild possible, it must be that zoos are breeding at least some species of endangered animals.
C
No zoos exploit wild animals or endanger the survival of species.
We don’t know whether there isn’t any zoo that exploits wild animals. We know that most new zoo animals are obtained through breeding programs, but not all of them.
D
Nearly all of the animals in zoos today were born in captivity.
We don’t know whether nearly all zoo animals were born in captivity. We know that most new zoo animals are obtained through breeding programs, but “most” could mean as little as 51 percent of animals.
E
The main purpose of zoos has shifted from entertainment to education.
We don’t know what would be the main purpose of zoos. We only know that they have served as educational resources and as entertainment.
Summary
Teachers enable students to learn geometry more easily by using graphical illustrations. This is because the illustrations provide students with an intuitive understanding of geometric concepts, which makes it easier to manipulate symbols. Graphically illustrating algebraic concepts would be equally effective, even though the deepest mathematical understanding is abstract.
Strongly Supported Conclusions
This is an “except” question and any strongly supported conclusion would be an incorrect answer. We’re looking for an answer that is unsupported or least supported. Some strongly supported conclusions could be:
Imagistic understanding is not the deepest level of mathematical understanding.
Some teaching strategies can be used to teach students both geometric and algebraic concepts.
Graphically illustrating geometric concepts is an effective teaching strategy.
Imagistic understanding is not the deepest level of mathematical understanding.
Some teaching strategies can be used to teach students both geometric and algebraic concepts.
Graphically illustrating geometric concepts is an effective teaching strategy.
A
Pictorial understanding is not the final stage of mathematical understanding.
This answer is strongly supported. We know from the stimulus that the deepest level, and therefore final stage, of mathematical understanding is abstract.
B
People who are very good at manipulating symbols do not necessarily have any mathematical understanding.
This answer is unsupported. We know from the stimulus that there are some people who are both good at manipulating symbols and have mathematical understanding. We don’t know if there are some people good at manipulating symbols but don’t have mathematical understanding.
C
Illustrating geometric concepts graphically is an effective teaching method.
This answer is strongly supported. We know that graphically illustrating these concepts is an effective teaching method from the first sentence.
D
Acquiring the ability to manipulate symbols is part of the process of learning geometry.
This answer is strongly supported. We know that this process is involved in learning geometry from the first sentence.
E
There are strategies that can be effectively employed in the teaching both of algebra and of geometry.
This answer is strongly supported. We know this because the stimulus tells us that using graphic illustrations would be “equally effective” for teaching algebraic concepts.
Summarize Argument
The president claims the Planning Board's estimate that businesses are leaving the region at a rate of four per week is an exaggeration. He supports this by saying that since there were never more than about a thousand businesses in the region, and no new businesses have moved in over the last ten years, they would have all disappeared by now if that estimate were accurate.
Identify and Describe Flaw
The president assumes that the Planning Board’s estimate has been the case for a long period of time. But just because business are leaving the region at a rate of four per week doesn’t mean that they have been leaving at this rate for many months or years. If business only started leaving at this rate very recently, the president’s argument falls apart.
A
focuses on what is going out of a system while ignoring the issue of what is coming into the system
The president doesn’t ignore the issue of what’s coming into the system. In fact, he explicitly states that “almost no new businesses have moved into our region or started up here over the last ten years.”
B
confuses a claim about a rate of change within a system with a claim about the absolute size of the system
The argument addresses a claim about the rate of change and a claim about the absolute size of the system, but the president doesn’t confuse these claims. Instead, he uses a claim about absolute size to refute the claim about the rate of change.
C
argues against a position simply by showing that the position serves the interest of the Planning Board
The president never claims that the Planning Board’s estimate serves their own interest.
D
treats a claim about what is currently the case as if it were a claim about what has been the case for an extended period
The president treats the claim that businesses are currently leaving the region at a rate of four per week as if it has been the case for an extended period of time. But perhaps businesses only began leaving at that rate very recently. If so, the president’s argument falls apart.
E
attacks what was offered as an estimate on the ground that it is not precise
The president never attacks the precision of the Planning Board’s estimate. Instead, he claims that the estimate is exaggerated.
Summarize Argument
The statistician claims there’s reason to be skeptical about the magazine’s claim that North Americans are more concerned with finances than politics. Why? Because a question on the survey was biased and because subscribers to the magazine might poorly represent North Americans in general.
Notable Assumptions
The statistician assumes conclusions based on a survey with a self-selecting sample and a biased question should be received skeptically. He assumes the survey question he quotes is biased in a way that could affect the conclusion based on the survey’s results.
A
The credibility of the magazine has been called into question on a number of occasions.
This is another reason to view the survey’s results with skepticism. It suggests the magazine has been accused of being careless or insincere, which doesn’t prove the magazine’s conclusion wrong, but does give a reason to be skeptical of it.
B
The conclusions drawn in most magazine surveys have eventually been disproved.
This is another reason to view the magazine’s conclusion with skepticism. It suggests magazine surveys in general are unreliable, which doesn’t prove this magazine’s conclusion is false, but gives a reason to be skeptical about it.
C
Other surveys suggest that North Americans are just as concerned about politics as they are about finances.
This introduces new evidence that conflicts with the magazine’s conclusion, giving more reason to doubt that conclusion.
D
There is reason to be skeptical about the results of surveys that are biased and unrepresentative.
This makes concrete the statistician’s assumption that a survey with an unrepresentative sample and a biased question should be viewed skeptically.
E
Other surveys suggest that North Americans are concerned not only with politics and finances, but also with social issues.
This is irrelevant. Neither the magazine nor the statistician assumes politics and personal finance are the only two issues North Americans care about. Concern about a third issue gives no reason to doubt the magazine’s conclusion, which compares interest in the two issues only.
Multiple sclerosis is an autoimmune disease: white blood cells attack the myelin sheath that protects nerve fibers in the spinal cord and brain. Medical science now has a drug that can be used to successfully treat multiple sclerosis, but the path that led medical researchers to this drug was hardly straightforward. Initially, some scientists believed attacks characteristic of multiple sclerosis might be triggered by chronic viral infections. So in 1984 they began testing gamma interferon, one of the body’s own antiviral weapons. To their horror, all the multiple sclerosis patients tested became dramatically worse. The false step proved to be instructive however.
Summary
Scientists thought multiple sclerosis (MS) was caused by viral infections. To test this hypothesis, they used gamma interferon—a tool the body uses to combat viral infections—to treat MS. This experiment, however, resulted in the MS patients’ conditions worsening.
Notable Valid Inferences
Gamma interferon makes MS worse.
A
Gamma interferon stops white blood cells from producing myelin-destroying compounds.
This is not compatible with the experiment’s results. If gamma interferon does what (A) claims, it would interfere with the mechanism that makes MS so destructive. This would likely improve MS patients’ conditions—this contradicts the experiment, which shows the opposite effect.
B
Administering gamma interferon to those without multiple sclerosis causes an increase in the number of white blood cells.
This could be true and may explain why gamma interferon makes MS patients’ conditions worse. By causing an increase in white blood cells, gamma interferon could increase the number of cells attacking the myelin sheath in MS patients.
C
Medical researchers have discovered that the gamma interferon level in the cerebrospinal fluid skyrockets just before and during multiple sclerosis attacks.
This could be true and may explain why gamma interferon makes MS patients’ conditions worse. It suggests an association between increased gamma interferon levels and MS attacks.
D
It has now been established that most multiple sclerosis sufferers do not have chronic viral infections.
This could be true. It suggests that scientists’ initial belief that MS is triggered by viral infections is incorrect. This could explain why gamma interferon, one of the body’s antiviral tools, is ineffective against it.
E
The drug now used to treat multiple sclerosis is known to inhibit the activity of gamma interferon.
This could be true and may explain why gamma interferon makes MS patients’ conditions worse. It suggests that inhibiting gamma interferon levels improves patients’ conditions—this is consistent with the finding that increasing gamma interferon levels worsens patients’ conditions.
Summarize Argument
The author concludes that a hard track allows for faster running than a soft track, provided the conditions are dry. Why? Because on a hard track, runners spend less time with their feet touching the ground, even though their steps are shorter.
Notable Assumptions
The author assumes that runners save more time by keeping their feet off the ground than they lose by taking shorter steps on a hard track. In addition, he assumes there’s no other feature of hard tracks that allows people to run faster on them.
A
Dry running conditions can be guaranteed for indoor track races only.
This implies the conclusion isn’t always relevant, not that the argument is incomplete. The author restricts his statements to dry tracks only.
B
In general, taller runners have greater average step length than shorter runners do.
This doesn’t say shorter runners would benefit from a softer track, because it’s possible the shorter step length allowed by the harder surface holds back runners of all heights equally.
C
Hard tracks enhance a runner’s speed by making it easier for the runner to maintain a posture that minimizes wind resistance.
This calls the argument into question even though it gives another reason to support the conclusion. Perhaps hard tracks make for faster running because they reduce wind resistance, not because they allow for more air time.
D
The tracks at which the world’s fastest running times have been recorded are located well above sea level, where the air is relatively thin.
This suggests elevation is another factor that can affect running speed, but gives no difference between hard and soft tracks suggesting the reasoning is incomplete. The author does not claim that track surface is the only variable that might affect running speed.
E
To remain in top condition, a soft track surface requires different maintenance procedures than does a hard one.
This doesn’t say a soft track is any more or less likely to remain in top condition, nor what effect a track in poor condition would have on running speed.
Summarize Argument
The author concludes that rerouting the sewage is pointless. Why? Because most lobsters are too short-lived to suffer from the gill diseases that rerouting the sewage would prevent.
Notable Assumptions
The author assumes there is no other worthwhile reason for the sewage to be rerouted. In particular, he assumes that if lobsters are not harmed by sewage-caused gill diseases, then there’s no use in trying to prevent them.
A
Contaminants in the harbor other than sewage are equally harmful to lobsters.
This strengthens the argument. If non-sewage contaminants are equally dangerous, then rerouting the sewage will not protect the lobsters much, if at all.
B
Lobsters, like other crustaceans, live longer in the open ocean than in industrial harbors.
This does not say lobsters live only in the open ocean. It’s possible the lobsters caught for human consumption live mainly in industrial harbors.
C
Lobsters breed as readily in sewage-contaminated water as in unpolluted water.
This strengthens the argument by eliminating one possible reason for the sewage to be rerouted.
D
Gill diseases cannot be detected by examining the surface of the lobster.
This is not relevant. There’s no indication the detection of gill diseases from the outside makes lobsters more or less healthy or dangerous.
E
Humans often become ill as a result of eating lobsters with gill diseases.
This is a reason to reroute the sewage. Though lobsters themselves may not suffer from sewage-contaminated water, humans eating them will.