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.