Summarize Argument
The author concludes that nuclear power plants are not economically feasible. He supports this by saying that nuclear plants are far more expensive to build than conventional power plants.
Notable Assumptions
The author assumes that nuclear power plants aren’t economically feasible, simply because they’re more expensive to build. He ignores any potential long-term benefits of nuclear power plants that might outweigh their building costs and make them more economically feasible over time.
For example, nuclear plants might last longer or need far less maintenance than conventional plants. He also assumes that the lower ongoing fuel costs of nuclear plants won't offset the higher initial building costs.
For example, nuclear plants might last longer or need far less maintenance than conventional plants. He also assumes that the lower ongoing fuel costs of nuclear plants won't offset the higher initial building costs.
A
Safety regulations can increase the costs of running both conventional and nuclear power plants.
Irrelevant— the author says that he isn’t addressing safety concerns. But even if he did address safety concerns, (A) shows that safety regulations increase the costs of both kinds of plants. This doesn’t strengthen the argument that nuclear plants aren’t economically feasible.
B
Conventional power plants spend more time out of service than do nuclear power plants.
This weakens the author’s argument by providing an economic benefit of nuclear plants. If conventional plants spend more time out of service, nuclear plants might be more economically feasible over time.
C
The average life expectancy of a nuclear power plant is shorter than that of a conventional one.
This provides an additional cost of nuclear power plants. If nuclear plants have a shorter lifespan than conventional plants, they may indeed be less economically feasible, since more would need to be built over time.
D
Nuclear power plants cost less to build today than they cost to build when their technology was newly developed.
Irrelevant— even if nuclear power plants are cheaper now, we still don't know if they are economically feasible. This fails to provide any other costs that would make them unfeasible.
E
As conventional fuels become scarcer their cost will increase dramatically, which will increase the cost of running a conventional power plant.
This weakens the argument that nuclear plants are not economically feasible. If the cost of conventional plants will increase dramatically, then nuclear plants might actually be more economically feasible over time.
Summarize Argument
The pundit concludes that our society values sports more than it values education. This is based on the claim that on average, athletes have a higher salary than teachers.
Identify and Describe Flaw
The pundit’s argument is flawed because it draws a broad conclusion from on a limited premise. The pundit assumes that just because teachers have lower average salaries than athletes, less money must be spent on education than sports overall. But this isn’t necessarily true. For example, there could be many more teachers than athletes, meaning education would be given a higher overall value.
A
presumes, without providing justification, that sports have some educational value
The pundit just doesn’t claim that sports have educational value.
B
fails to consider that the total amount of money spent on education may be much greater than the total spent on sports
The pundit concludes that society values sports over education because athletes’ salaries are higher than teachers’. But that doesn’t necessarily follow. There could be more expenses in education than in sports overall—for example, there may be many more teachers than athletes.
C
fails to consider both that most teachers are not in the classroom during the summer and that most professional athletes do not play all year
This consideration doesn’t impact how much money society spends on education compared to sports, so it’s irrelevant.
D
compares teachers’ salaries only to those of professional athletes rather than also to the salaries of other professionals
The pundit is drawing a conclusion about the value given to sports versus education, so it’s not relevant to compare teachers’ salaries to those of any other professionals than athletes.
E
fails to compare salaries for teachers in the pundit’s society to salaries for teachers in other societies
The pundit is only drawing a conclusion about a phenomenon within this society, not making a comparison with other societies.
Summary
Gauge field theory is an area of math that, although investigated in the 19th century, has only recently been applied. Differential geometry is another area of math that was investigated in the 19th century, which was a long time before Einstein determined that one of its offspring, tensor analysis, was appropriate for the theory of general relativity.
Strongly Supported Conclusions
Some fields of math may be applicable many years after they are first investigated.
Some fields of math relevant to a problem may have been discovered many years in the past.
Some fields of math relevant to a problem may have been discovered many years in the past.
A
Applications of some new theories or techniques in mathematics are unrecognized until long after the discovery of those theories or techniques.
Strongly supported. The stimulus presents examples of areas of math that were first investigated many years before they were used for certain applications. This is evidence that those particular applications were unknown for a long time.
B
Mathematicians are sometimes able to anticipate which branches of their subject will prove useful to future scientists.
Unsupported. The stimulus doesn’t suggest that any mathematician was able to anticipate which parts of their subject would be useful to future scientists. We don’t have any statements indicating the expectations or thoughts from mathematicians about the future.
C
The discoveries of modern physics would not have been possible without major mathematical advances made in the nineteenth century.
Unsupported. Although we know that the math fields discussed in the stimulus were useful for certain problems related to physics, that doesn’t imply that modern physics wouldn’t have been discovered without those fields.
D
The nineteenth century stands out among other times as a period of great mathematical achievement.
Unsupported. The stimulus doesn’t compare the 19th century with other centuries regarding the level of mathematical achievement.
E
Mathematics tends to advance more quickly than any of the physical sciences.
Unsupported. The stimulus doesn’t compare math to other fields regarding the speed of its advancement.
Summarize Argument: Counter-Position
The argument concludes that no birds descended from dinosaurs, counter to a common claim. This is based on the discovery that some bird fossils predate the fossils of dinosaurs from which birds were previously thought to have descended, so those birds couldn’t have descended from those dinosaurs.
Identify and Describe Flaw
The argument takes evidence proving that certain birds didn’t descend from certain dinosaurs to support a conclusion that no birds descended from any dinosaurs. However, it’s still totally possible that other birds were descended from those birdlike dinosaurs, or even that the newly discovered birds were descended from even older dinosaurs.
A
draws a generalization that is broader than is warranted by the findings cited
The argument generalizes that the entire hypothesis of birds descending from dinosaurs must not be true, based on findings that only disprove certain birds descending from certain dinosaurs.
B
rejects the consensus view of experts in the field without providing any counterevidence
The argument rejects a described consensus view of experts, but this is based on the provided counterevidence of bird fossils which predate the fossils of their claimed dinosaur ancestors.
C
attacks the adherents of the opposing view personally instead of addressing any reason for their view
The argument doesn’t make any personal attacks, and does address at least one reason for the opposing view.
D
fails to consider the possibility that dinosaurs descended from birds
The argument only attempts to counter the hypothesis that birds descended from dinosaurs. The possibility that dinosaurs descended from birds is irrelevant (and clearly absurd).
E
ignores the possibility that dinosaurs and birds descended from a common ancestor
There’s no need for the argument to consider this possibility. The argument is only concerned with countering the hypothesis that birds descended from dinosaurs, not with providing any other hypotheses about evolution.
"Surprising" Phenomenon
How can a report claiming erosion is light and a report claiming erosion is heavy both be accurate?
Objective
Any hypothesis resolving this discrepancy must state a difference between the two reports that explains how they can both be correct. This difference will not question the accuracy of either study, but will allow for erosion to be both heavy and relatively light in this region.
A
Neither report presents an extensive chemical analysis of the soil in the region.
This speaks to the reports’ methodologies without reconciling their different results. The author states that both reports are accurate, so the validity of their conclusions is not in question.
B
Both reports include computer-enhanced satellite photographs.
This speaks to the reports’ methodologies without reconciling their different results. Both reports are accurate, whether or not they include satellite photographs.
C
One report was prepared by scientists from a university, while the other report was prepared by scientists from a private consulting firm.
This refers to the people who produced the reports without addressing their findings. It does not explain how their conclusions can be simultaneously accurate.
D
One report focuses on regional topsoil erosion, while the other report focuses on riverbank erosion resulting from seasonal floods.
This explains why both reports can be accurate. They studied different types of erosion, so their results are not in conflict.
E
One report cost nearly twice as much to prepare as did the other report.
This speaks to the resources used to prepare the reports without addressing their findings. Both reports are accurate, regardless of their cost.
Summarize Argument: Counter-Position
The letter concludes that the evidence supports increasing speed limits, even though areas with lower speed limits also have lower vehicle fatality rates. This is based on the observation that fatality rates are rising in areas with lower speed limits.
Identify and Describe Flaw
The letter’s argument is flawed because it draws a conclusion about the safety of areas with low speed limits relative to other areas, while only considering evidence about areas with low speed limits. In other words, the argument fails to consider whether the same increase in fatality rates is happening in areas with higher speed limits.
A
bases its conclusion on findings from the same article that it is criticizing
The argument does base its conclusion on findings from the article which it criticizes, but this isn’t a flaw, because the argument seeks to prove that the article misinterpreted the evidence. So, it actually has to show that the same evidence leads to a different conclusion.
B
fails to consider the possibility that automobile accidents that occur at high speeds often result in fatalities
Whether high-speed accidents “often” cause fatalities isn’t relevant to the argument. The argument is specifically about the fatality rates in low-speed-limit versus high-speed-limit areas, and this possibility wouldn’t help to make that determination.
C
fails to consider the possibility that not everyone wants to drive faster
Whether or not people want to drive faster is irrelevant to the argument, because it doesn’t impact the issue of whether raising speed limits would be safer.
D
fails to consider the possibility that the vehicle-related fatality rates in other areas are also rising
The argument draws a conclusion that a higher speed limit is safer based only on evidence about rising fatality rates in low-speed-limit areas. Without knowing whether fatality rates are also rising in high-speed-limit areas, this just isn’t enough to support the conclusion.
E
does not present any claims as evidence against the opposing viewpoint
The argument does present claims as evidence against the opposing viewpoint: specifically, the increasing fatality rate in low-speed-limit areas.