Summarize Argument
The author concludes that we should raise taxes. This is because the only way for homelessness to disappear is for the government to provide the homeless with housing. In order for the government to provide the homeless with housing, this requires increased taxation.
Notable Assumptions
The author assumes that if something is necessary for making homelesness disapperar, it’s something we should do.
A
Only if a measure is required to solve a problem should it be adopted.
This tells us that a thing’s being required to solve a problem is necessary in order for it to be something we should adopt. But (A) doesn’t establish that we actually should do the thing. (A) would be correct if it had started with “If” rather than “Only if.”
B
Only if a measure is sufficient to solve a problem should it be adopted.
We are not told about a measure that’s sufficient to solve a problem. We know what’s required to solve homelessness — government building housing and taxation. But we don’t know these are sufficient. (B) also doesn’t help reach the conclusion that something should be adopted.
C
If a measure is required to solve a problem, then it should be adopted.
This helps connect the premises to the conclusion. We know increased taxation is necessary to solve homelessness. Based on (C), we can then conclude that we should increase taxation.
D
If a measure is sufficient to solve a problem, then it should be adopted.
We are not told about any measure that’s sufficient to solve the problem of homelessness. We know what’s required to solve it — government building housing and taxation. But we don’t know these are sufficient to solve homelessness.
E
If a measure is sufficient to solve a problem, any steps necessitated by that measure should be adopted.
We are not told about any measure that’s sufficient to solve the problem of homelessness. We know what’s required to solve it — government building housing and taxation. But we don’t know these are sufficient to solve homelessness.
Summary
We are discussing ALL mammalian species and how play is related to their brain development. At the time a young mammal is most playful, it is also growing brain connections related to movement, posture, and social response at the fastest speed. These brain connections created by play become essential for success as an adult.
Strongly Supported Conclusions
Play is good for mammals’ brain development and their success as adults.
Young mammals’ play is somewhat related to the movement, posture, and social response necessary for survival and well-being as an adult.
Any given mammal species (such as a bear or a human) has a relationship between play, neural development, and adult success and well being.
(Note: these are possible wrong answers - we’re looking for the answer choice that is LEAST supported - so it won’t be on the strong side of the support spectrum.
Young mammals’ play is somewhat related to the movement, posture, and social response necessary for survival and well-being as an adult.
Any given mammal species (such as a bear or a human) has a relationship between play, neural development, and adult success and well being.
(Note: these are possible wrong answers - we’re looking for the answer choice that is LEAST supported - so it won’t be on the strong side of the support spectrum.
A
Young mammals of species that are preyed on by other animals are likely to engage in forms of sudden mock flight, bolting away from locations where no predators are to be found.
Strongly supported: We know play creates neural connections important for survival as an adult. Running from predators would be an important survival skill for these species. This play would strengthen their survival skills, and therefore, it fits the description in the stimulus.
B
The young of nonmammalian species such as fish, reptiles, and birds do not normally engage in playful behavior that serves the function served by play in the development of young mammals.
Unsupported: The information in the stimulus does not allow conclusions about nonmammalian species. There is no information about this group to conclude about what they do.
C
Adult mammals are more likely to engage in interactive play with their young if they engaged in similar forms of play when they themselves were young.
Strongly supported: The idea in the stimulus is that play strengthens skills by building neural connections. Mammals who played early in life would develop neural connections that would strengthen their ability to play with their young - a skill related to well-being.
D
Mammals that cannot engage in certain common forms of play when young are likely to show certain deficits that limit their subsequent success as adults.
Strongly supported: We know the neural connections are indispensable / necessary for success. If mammals don’t develop them through play, then they are likely to be limited as adults.
E
Young mammals of predatory species tend to practice in their play inoffensive versions of motions and actions that are useful in finding and catching prey when these mammals become adults.
Strongly supported: Like answer choice A, this shows a group building skills through play that will be necessary as adults. They would build the neural connections involved in hunting, which would be important as adults to find and catch food.
"Surprising" Phenomenon
Why do cigarette smokers who do not chew tobacco have a higher incidence of heart attacks and high blood pressure than nonsmokers who chew tobacco (and who are exposed to the same amount of nicotine)?
Objective
The right answer will be a hypothesis that does not offer a useful difference between cigarette smokers who do not chew tobacco and nonsmokers who chew tobacco. The incorrect answers will offer useful differences between these two groups, providing reasons for why the cigarette smokers showed a higher incidence of heart attacks and high blood pressure, even though both groups were exposed to the same amount of nicotine.
A
People who smoke but do not chew tobacco tend to exercise less than those who chew tobacco but do not smoke.
This could help resolve the discrepancy. The nonsmokers who chew tobacco exercise more, which presumably lowers their risk of heart attacks and high blood pressure compared to the smokers who do not chew tobacco.
B
Chemicals other than nicotine present in chewing tobacco but not present in cigarette smoke mitigate the effects that nicotine has on the cardiovascular system.
This could help resolve the discrepancy. The nonsmokers who chew tobacco ingest chemicals that mitigate nicotine’s harmful effects, while the smokers do not. This could decrease the risk of heart attacks and high blood pressure in nonsmokers who chew tobacco.
C
People who chew tobacco but do not smoke tend to have healthier diets than those who smoke but do not chew tobacco.
This could help resolve the discrepancy. The healthier diets of the nonsmokers who chew tobacco presumably decrease their risk of heart attacks and high blood pressure compared to the smokers who do not chew tobacco.
D
Chemicals other than nicotine present in chewing tobacco but not present in cigarette smoke can cause cancer.
This would not help resolve the discrepancy, and is therefore the correct answer. (D) discusses cancer, not heart attacks and high blood pressure.
E
Chemicals other than nicotine present in cigarette smoke but not present in chewing tobacco raise blood pressure.
This could help resolve the discrepancy. If cigarette smokers are ingesting chemicals that raise blood pressure, it would help explain why they have a higher incidence of high blood pressure.
Numismatist: In medieval Spain, most gold coins were minted from gold mined in West Africa, in the area that is now Senegal. The gold mined in this region was the purest known. Its gold content of 92 percent allowed coins to be minted without refining the gold, and indeed coins minted from this source of gold can be recognized because they have that gold content. The mints could refine gold and produced other kinds of coins that had much purer gold content, but the Senegalese gold was never refined.
"Surprising" Phenomenon
Why did merchants selling goods often specify that payment should be in coins minted from Senegalese gold?
Objective
The right answer will be a hypothesis for why merchants preferred payment in coins minted from Senegalese gold. This hypothesis will explain a key difference between coins minted from Senegalese gold and coins minted from other types of gold. It could reference the fact that, as the stimulus states, Senegalese gold has a high gold content and was never refined.
A
Because refined gold varied considerably in purity, specifying a price as a number of refined-gold coins did not fix the quantity of gold received in payment.
(A) says refined-gold coins are inconsistent or unreliable in their value because the purity of refined gold varies. This explains merchants’ preference for Senegalese gold, which does not need to be refined and therefore lacks these inconsistencies, making it more reliable.
B
During this period most day-to-day trading was conducted using silver coins, though gold coins were used for costly transactions and long-distance commerce.
The prevalence of silver coins in trade transactions does not explain why merchants often specified that payment should be in the coins minted from Senegalese gold.
C
The mints were able to determine the purity, and hence the value, of gold coins by measuring their density.
The mints’ ability to determine the value of gold coins does not explain why merchants, who are unrelated to the mints, would often specify that payment should be in the coins minted from Senegalese gold.
D
Since gold coins’ monetary value rested on the gold they contained, payments were frequently made using coins minted in several different countries.
Payments commonly being made using coins minted in different countries does not explain merchants’ preference for coins minted from Senegalese gold. The question stem does not say the merchants preferred coins minted in Spain; they preferred coins minted from Senegalese gold.
E
Merchants obtaining gold to resell for use in jewelry could not sell the metal unless it was first refined.
This is not helpful for explaining the merchants’ preference. (E) seems to imply that merchants would have a preference against Senegalese gold coins, as Senegalese gold was never refined and could therefore not be resold for use in jewelry.
Summary
The argument concludes that lizards did not evolve from anthracosaurs. How do we know? Because we haven’t found anthracosaur fossils in rocks older than 300 million years, but we recently found a 340-million-year-old lizard fossil. And of course, lizards could have only evolved from creatures that predated lizards.
Notable Assumptions
The argument assumes that there are no anthracosaur fossils that are older than 340 million years. If such a fossil existed, the support for the conclusion would be destroyed, because we could no longer claim that lizards predate anthracosaurs.
A
unknown anthracosaur fossils older than 340 million years
The argument tries to establish that lizards predate anthracosaurs to conclude that lizards can’t have evolved from anthracosaurs. However if these fossils did exist, then we couldn’t establish that lizards predate anthracosaurs, so the conclusion would be unsupported.
B
unknown lizard fossils older than 340 million years
The argument relies on the idea that lizards predate anthracosaurs because of each group’s oldest known fossils. Having even older lizard fossils wouldn’t change this, so like (E), this isn’t necessary.
C
known lizard fossils that predate some anthracosaur fossils
The argument explicitly states that we now know of a lizard fossil which predates even the oldest anthracosaur fossils, so this assumption would just be contradictory.
D
known anthracosaur fossils that predate some lizard fossils
The argument relies on the ages of the oldest known fossils for each group, so just saying that some anthracosaur fossils predate some lizard fossils is irrelevant.
E
known lizard fossils whose age is uncertain
Like (B), this is irrelevant because the argument has already established that the oldest known lizard fossil predates the oldest known anthracosaur fossil, and this doesn’t add anything useful.
Summary
Habitat Conservation Plans (HCPs) allow developers to use land inhabited by endangered species in exchange for preserving some habitat or replacement land nearby. Some members of endangered species are lost, but the developer ensures that the remaining animals will be protected. Environmentalists like that HCPs secure compromise from developers. Developers prefer HCPs over more restrictive prohibitions.
Strongly Supported Conclusions
Environmental laws should reflect a compromise between land developers and environmentalists.
A
In order to avoid protracted legal battles environmentalists should compromise with developers.
We don’t know whether the environmentalists or land developers would initiate legal battles with each other.
B
Developers should adhere only to those environmental laws that are not overburdensome.
We don’t know if developers should only adhere to laws that are not overburdensome. The environmentalists may prefer that land developers adhere to any and all environmental laws.
C
Laws should not be designed to serve the interests of all the parties concerned since they are often so weak that no one’s interest is served well.
As the stimulus describes, HCPs do serve the interests of all concerned parties. Environmentalists are served by securing compromise from developers, and developers are served because the prefer HCPs over more restrictive laws.
D
Laws should be fashioned in such a way as to reconcile the interests of developers and environmentalists.
HCPs do serve as a compromise between developers and environmentalists.
E
The most effective means of preserving endangered species is to refrain from alienating property owners.
We don’t know what the most effective means of protecting endangered species is. HCPs are just one way we are told could help this purpose.
Summarize Argument: Phenomenon-Hypothesis
The consumer advocate concludes that antivirus companies’ warning about a destructive computer virus was a “fraud.” Why? Because there weren’t many actual cases of damage from that virus, and yet the companies sold many antivirus programs. According to the advocate, this shows that the warning was just meant to increase sales.
Identify and Describe Flaw
The consumer advocate uses an imbalance between antivirus sales and cases of damage from a virus as evidence that antivirus companies were dishonest about the risk posed by the virus. This ignores the possible alternative explanation that the antivirus programs worked, and without all those sales, the virus would have caused much more damage.
A
restates its conclusion without attempting to offer a reason to accept it
The argument does offer support for its conclusion: the claim that there were way more antivirus sales than actual cases of harm from this virus.
B
fails to acknowledge that antivirus programs might protect against viruses other than the particular one described
The argument doesn’t acknowledge this possibility, but that isn’t a flaw because the argument is specifically about the particular virus described. Whether the antivirus programs are effective against other viruses is just irrelevant.
C
asserts that the occurrence of one event after another shows that the earlier event was the cause of the later one
The advocate’s argument isn’t trying to establish the cause of a correlation. There also just aren’t any earlier and later events discussed.
D
uses inflammatory language as a substitute for providing any evidence
The argument does provide evidence for its conclusion: the imbalance between antivirus sales and actual harm done by the virus.
E
overlooks the possibility that the protective steps taken did work and, for many computers, prevented the virus from causing damage
The argument never addresses this possibility, and instead just assumes without any reason that the reason the virus didn’t do much harm is because it was never harmful. However, if the antivirus programs were effective, that really undermines the argument.
Summary
Toddlers may bite without acting maliciously. Children may bite when they want a toy because the children feel the person with the toy is preventing them from having it.
Strongly Supported Conclusions
Toddlers who bite people to take a toy may not be acting maliciously. Toddlers may use biting as a means to an end.
A
Biting people is sometimes a way for toddlers to try to solve problems.
This answer is strongly supported because the stimulus gives us an example of this playing out. Toddlers have the problem of wanting a toy, and they use biting as a way of acquiring the toy to solve the problem.
B
Toddlers sometimes engage in biting people in order to get attention from adults.
This is unsupported because we only know that toddlers biting may be trying to get a toy. We don’t know that they are trying to attract attention, and we also don’t know that they are trying to get attention specifically from adults.
C
Toddlers mistakenly believe that biting people is viewed as acceptable behavior by adults.
This is unsupported because the stimulus provides us no information on adults’ attitudes toward biting. It also gives us no information on how toddlers predict adults will view biting.
D
Toddlers do not recognize that by biting people they often thwart their own ends.
This is unsupported because the stimulus fails to tell us whether or not toddlers are successful in biting to acquire toys.
E
Resorting to biting people is in some cases an effective way for toddlers to get what they want.
This is unsupported because the stimulus avoids telling us the outcome of biting. We don’t know whether or not biting successfully leads to getting the toys toddlers want.
Summary
The physicians conclude that anyone whose skin becomes irritated when injected with tuberculosis proteins has had tuberculosis. This is because people’s immune systems recognize proteins from bacteria that previously infected them. Furthermore, this immune system reaction also occurs (and leads to skin irritation) when someone has had tuberculosis and is then injected with tuberculosis proteins.
Notable Assumptions
The premises establish tuberculosis infection as a sufficient condition for skin irritation from this test, but not a necessary condition. However, the conclusion treats infection as being necessary. This means the physicians are assuming that there is no other reason someone’s skin would become irritated when injected with tuberculosis proteins, other than having had tuberculosis.
A
All of the proteins present in disease-causing bacteria can be recognized by the body’s immune system.
The argument is only concerned with the proteins in tuberculosis bacteria, so this kind of claim about all proteins in all disease-causing bacteria is too broad to be necessary.
B
Localized skin irritations are a characteristic symptom of tuberculosis in most people.
Whether or not skin irritation is usually a symptom of actual tuberculosis infection is irrelevant, because the argument is only concerned with reactions to the tuberculosis test.
C
The ability of the proteins present in the tuberculosis bacterium to trigger the skin irritation is exclusive to that bacterium.
In other words, there is no other bacterium which would lead to skin irritation when someone is injected with tuberculosis proteins. This is necessary because otherwise, we couldn’t conclude that a reaction meant tuberculosis and not some other bacterium.
D
Some people who have been injected with proteins extracted from the tuberculosis bacterium will contract tuberculosis as a result of the injection.
Whether or not it’s possible to get tuberculosis from being injected with tuberculosis proteins is irrelevant to whether a skin reaction truly indicates tuberculosis.
E
The body’s immune system cannot recognize infectious bacteria unless there are sufficient quantities of the bacteria to cause overt symptoms of disease.
What exactly it means to be “infected” by bacteria such that your immune system will recognize those bacteria isn’t relevant, because the argument doesn’t depend on that exact of a definition of “infected.”
A
When an anticounterfeiting technique depends on the detection of counterfeits by experts, the cost of inspection by experts adds significantly to the cost to society of that technique.
While the microprinting technique is cheaper when creating bills, it requires expert inspection. Expert inspection is costly, so microprinting might not in fact be cheaper overall. This strengthens the case for the special ink technique.
B
For any anticounterfeiting technique to be effective, the existence of anticounterfeiting techniques should be widely broadcast, but the method by which counterfeits are detected should be kept secret.
This applies to both techniques in question. We need to strengthen the case for special ink.
C
The process of microprinting paper currency involves fewer steps than does the printing of paper currency with the special ink.
This probably reinforces the notion that microprinting is cheaper. We’re looking to strengthen the case for special ink.
D
Before photocopying technology existed, most counterfeits of paper currency were accomplished by master engravers.
We don’t care about what happened before photocopying. We’re interested in microprinting and special ink.
E
Many criminals do not have access to the advanced photocopiers that are needed to produce counterfeits of microprinted paper currency that cashiers will accept as real.
This strengthens the case for microprinting. We’re trying to strengthen the case for special ink.