Summary
Simultaneous use of adjacent runways at the airport is not allowed when visibility is poor because the runways are too close together. The airport allows 30 planes per hour to land when weather is poor. 60 planes can land per hour in good weather. Airline schedules assume good weather, so bad weather creates delays.
Strongly Supported Conclusions
One cause of delays would go away if the adjacent runways were not too close together or if the weather were always good. Airline schedules assume that 30 planes per hour can land at the airport.
A
In poor weather, only half as many planes are allowed to land each hour on any one runway at the airport as are allowed to land on it in good weather.
This is unsupported because each individual runway may support the same number of airplanes regardless of the weather. When weather is bad, however, only one runway can be used at a time.
B
When the weather at the airport is good it is likely that there are planes landing on two adjacent runways at any given time.
This is unsupported because although both adjacent runways can be used at the same time when weather is good, we don’t know that planes are likely landing at any given time. We only know that both lanes are open, not that they are likely to have planes at any moment.
C
If any two of the airport’s runways are used simultaneously, serious delays result.
This is unsupported because serious delays are a product of one of the adjacent runways being closed off when weather is bad, not because two runways are being used.
D
Airlines using the airport base their schedules on the assumption that more than 30 planes an hour will be allowed to land at the airport.
This is strongly supported because we know that airlines base their assumption on good weather, and in good weather, more than 30 planes are allowed to land per hour.
E
In good weather, there are few if any seriously delayed flights at the airport.
This is unsupported because we only know that bad weather is one of the causes of delays. There may be several other causes of delays even when the weather is good that we aren’t aware of from the stimulus.
Summarize Argument
The author concludes that the bridge renovation wasted taxpayers’ money. This is based on the fact that a commission reported that the Souther Tier Project was wasteful, and the bridge renovation was a part of that project.
Identify and Describe Flaw
The author assumes that what applies to the whole (Souther Tier Project) must apply to a part(the bridge renovation). This overlooks the possibility that the bridge renovation might not have been a waste, even if the overall project was a waste. Perhaps the project was wasteful because of a different component besides the bridge renovation.
A
infers that a part has a certain quality merely on the grounds that the whole to which it belongs has that quality
The argument concudes that a part (bridge renovation) has a certain quality (waste of money) merely on the grounds that the whole to which it belongs (Southern Tier Project) has that quality.
B
draws a general conclusion about government waste on the basis of a single instance of such waste
The conclusion is not about government waste in general. It’s about the bridge renovation and whether that specific thing was wasteful.
C
attacks the mayor’s character rather than assessing the strength of the evidence supporting the mayor’s claim
The argument does not attack the character of the mayor. The evidence concerns the Southern Tier Project being a waste of money, and the fact that the bridge renovation was part of the project.
D
puts forward evidence that presupposes an important part of the claim that the argument attempts to support
(D) describes circular reasoning. No part of the evidence assumes the truth of that conclusion. The conclusion is that the bridge renovation was a waste of money; the evidence does not presuppose that this is true.
E
rejects a position on the grounds that the motives of the person who has advanced the position were not disinterested
The author does not comment on the motives of the mayor.
Summary
The stimulus can be diagrammed as follows:
Notable Valid Inferences
Some of the films that were shown at the Lac festival won prizes at international film festivals.
All the films that won prizes at the Lac festival were Canadian.
Some of the films that won prizes at international film festivals this year were Canadian.
All the films that won prizes at the Lac festival were Canadian.
Some of the films that won prizes at international film festivals this year were Canadian.
A
This year, most of the Canadian films that were shown at international film festivals won prizes at the Lac Nichoutec Film Festival.
Could be false. We don’t know what percentage of the Canadian films shown at international festivals won at the Lac Nichoutec Film Festival. What if the international film festivals showed 1000 Canadian films, and only 10 films total won prizes at the Lac Nichoutec Film Festival?
B
Most of the Canadian films produced this year were shown at the Lac Nichoutec Film Festival.
Could be false. The stimulus gives us no information about what percentage of Canadian films produced this year were shown at the Lac Nichoutec Film Festival.
C
Some of the films that won prizes at international film festivals this year were Canadian films.
Must be true. When we chain the conditional claims, the “some” relationship becomes clear: all films that won at the Lac Festival were Canadian, and most of those won prizes at international festivals, so at least those films both won at international festivals and are Canadian.
D
This year, not every film that won a prize at the Lac Nichoutec Film Festival was also shown at an international film festival.
Could be false. It’s very possible that every film that won a prize at the Lac Nichoutec Film Festival was also shown at an international film festival—after all, most of them won at the international festivals!
E
This year, at least one film that won a prize at an international film festival was not shown at the Lac Nichoutec Film Festival.
Could be false. Maybe the Lac Nichoutec movies were the best films in the world this year and every international festival winner was shown there! Maybe they were the only movies submitted to the international film festivals! The stimulus does nothing to make this impossible.
Summarize Argument: Counter-Position
The author concludes that the cynicism of contemporary journalists does not undermine our society’s well-being. This is based on the fact that journalists have always been cynics.
Identify and Describe Flaw
The author assumes that the well-being of society has not been undermined in the past due to journalists’ cynicism. This overlooks the possibility that society has been undermined from the cynicism that has always existed.
A
widespread cynicism is beneficial to the well-being of society
We’re concerned with the cynicism of journalists. The effects of “widespread” cynicism, which would include others besides journalists, doesn’t affect the argument’s reasoning. Also, cynicism being beneficial doesn’t help show that it can undermine well-being.
B
cynicism about the motives of powerful people increases with the amount of information one has about them
Whether cynicism increases the information one has about someone has no impact on whether journalists’ cynicism undermines society.
C
the work of contemporary journalists reflects a cynicism that is not really genuine
Whether journalists’ cynicism is genuine or not genuine is irrelevant; what matters is whether that cynicism undermines the well-being of society.
D
any accurate description of human behavior portrays it as selfish
Whether accurate descriptions of behavior portray such behavior has selfish has no impact on whether journalists’ cynicism undermines society’s well-being.
E
cynicism of this type on the part of journalists has always had a negative effect on the well-being of society
This possibility, if true, shows that the fact journalists have always been cynics does not prove their cynicism doesn’t undermine society’s well-being. This well-being has always been undermined as a result of journalists’ cynicism.
Ditalgame Corporation’s computer video games are subject to widespread illegal copying. To combat this piracy, Ditalgame will begin using a new copy protection feature on its games. Ditalgame’s president predicts a substantial increase in sales of the company’s games once the new copy protection feature is implemented.
Summarize Argument
The president concludes that Ditalgame’s sales will increase significantly once the new copy protection feature is added. This is because Ditalgame's games are frequently pirated, so they are implementing a new feature to help prevent piracy.
Notable Assumptions
The president assumes that the feature will directly boost sales without explaining how. He assumes piracy significantly affects sales, rather than other factors like poor game quality. He also seems to assume that some pirates will buy Ditalgame’s games when piracy is no longer an option, rather than choosing other games to pirate or buy.
A
Ditalgame has spent millions of dollars developing the new copy protection feature, and the company can recoup these costs only if its sales increase substantially.
This suggests that Ditalgame needs more sales in order to make an overall profit. But the president’s conclusion is only about whether Ditalgame will increase its sales. (A) fails to address the connection between reduced piracy and increased sales.
B
Over the last several years, the market for computer games has grown steadily, but Ditalgame’s share of that market has shrunk considerably.
The fact that Ditalgame’s share of the game market has shrunk doesn’t tell us whether the copy protection feature will increase sales. (B) fails to address the connection between reduced piracy and increased sales.
C
The copy protection feature causes a copied game to be playable just long enough for most people to come to enjoy it so much that they decide they have to have it.
This provides one explanation for how the copy protection feature could cause a significant increase in sales: by leading some pirates to buy the game.
D
Game Review Monthly, the most commonly read magazine among people who frequently copy computer games, generally gives favorable reviews to Ditalgame games.
This might help explain why Ditalgame’s games are subject to widespread illegal copying, but it doesn’t help explain how the new copy protection feature will increase sales. (D) fails to address the connection between reduced piracy and increased sales.
E
Computer games produced by Ditalgame are copied more frequently than computer games produced by Ditalgame’s main competitors.
We already know that Ditalgame’s games “are subject to widespread illegal copying.” It doesn’t matter if they’re copied more than their competitors’ games. (E) fails to address the connection between reduced piracy and increased sales.
Summary
In a party game, Person A steps out of the room, believing that Person B is sharing a recent dream with the rest of the group. Person A comes back and tries to reconstruct the dream by asking yes-or-no questions. But in reality, no dream was shared. The group just answers based on an arbitrary rule. Surprisingly, Person A usually makes up a dream story that is both coherent and clever, even though the “real” dream was never explained.
Strongly Supported Conclusions
People tend to try to make sense out of information, even when there is no sense behind it.
The belief that something is coherent and meaningful can cause someone to infuse that thing with coherence and meaning.
The belief that something is coherent and meaningful can cause someone to infuse that thing with coherence and meaning.
A
The presumption that something has order and coherence can lead one to imbue it with order and coherence.
This is strongly supported. Person A presumes that the dream has order and coherence, even though there is not really any dream at all. Nevertheless, because Person A presumes this, she then imbues her own construct of the dream with order and coherence.
B
One is less apt to reach a false understanding of what someone says than to make no sense out of it at all.
This is unsupported. The stimulus is not drawing a comparison between these two scenarios. Also, Person A does attempt to make sense out of the arbitrary answers that are given to her.
C
Dreams are often just collections of images and ideas without coherent structures.
This is unsupported. The stimulus tells us nothing about the structure of dreams. In fact, there is no dream related in the stimulus at all.
D
Interpreting another person’s dream requires that one understand the dream as a coherent narrative.
This is unsupported. Person A is not interpreting Person B’s dream; she is simply trying to reconstruct it. Also, again, there is not actually any dream related by Person B at all.
E
People often invent clever and coherent stories to explain their behavior to other people.
This is unsupported. Person A may be inventing a coherent story, but she is not trying to explain her behavior to other people. Rather, she is trying to reconstruct Person B’s supposed dream.
Summarize Argument
The author concludes that pollution is not eliminating many amphibian species every year. This is based on the fact that last year, biologists have learned that there are many more species of amphibians in existence than had previously been known.
Identify and Describe Flaw
The fact that we have discovered additional amphibian species doesn’t relate to whether pollution is killing amphibian species. Discovery of amphibian species doesn’t mean that there’s been an actual increase in the species that exist. So pollution can be killing amphibian species even as we are discover new species that we didn’t know about.
A
kinds of things and the things that are of those kinds
“Kinds of things” refers to different kinds of amphibians. “Things that are of those kinds” refers to examples of the kinds of amphibians. The author doesn’t confuse these two. The confusion relates to learning about new species vs. an actual increase in the number of species.
B
a condition necessary for a phenomenon and one that is sufficient for it
The author’s argument doesn’t rely on conditional reasoning, so there’s no confusion of necessary and sufficient conditions.
C
a cause and an effect
The author doesn’t conclude that one thing causes another, so the flaw doesn’t concern a reversal of cause and effect.
D
a correlation between two phenomena and a causal relationship between them
The author doesn’t conclude that one thing causes another, so the flaw doesn’t concern going from correlation to cause.
E
changes in our knowledge of objects and changes in the objects themselves
The author confuses changes in our knowledge of the number of amphibian species with changes in the number of amphibian species. The author mistakenly thinks our discovery of new species indicates that pollution isn’t killing species.