Columnist: The failure of bicyclists to obey traffic regulations is a causal factor in more than one quarter of the traffic accidents involving bicycles. Since inadequate bicycle safety equipment is also a factor in more than a quarter of such accidents, bicyclists are at least partially responsible for more than half of the traffic accidents involving bicycles.
Summarize Argument
The columnist concludes that bicyclists are partly responsible for more than half of all bike-related traffic accidents. She supports this by saying that bikers not following traffic rules contributes to more than a quarter of these accidents, and poor bike safety equipment is also a factor in more than a quarter of these accidents.
Identify and Describe Flaw
The columnist concludes that bicyclists are partly to blame for over half of bike-related accidents because two factors— not following traffic rules and using poor safety equipment— each contribute to more than a quarter of these accidents. Her reasoning is flawed because she assumes that these factors never overlap, or that only one factor contributes to each accident. But if some of these accidents involve both factors, she can't claim that bicyclists are responsible for over half of them.
A
presumes, without providing justification, that motorists are a factor in less than half of the traffic accidents involving bicycles
The columnist doesn’t address motorists or assume that they’re a factor in less than half of the accidents. She says bicyclists are at least partially responsible for more than half of the accidents, so motorists could be partially responsible for these accidents as well.
B
improperly infers the presence of a causal connection on the basis of a correlation
The columnist doesn’t draw a causal conclusion based on a mere correlation. Instead, she infers a detail about a causal relationship on the basis of a premise that does establish something as “a causal factor.”
C
fails to consider the possibility that more than one factor may contribute to a given accident
The columnist assumes that only one of the factors contributes to each accident. But if not following traffic rules and using poor safety equipment both contribute to some accidents, then it might not be true that bicyclists are partly responsible for over half of the accidents.
D
fails to provide the source of the figures it cites
The columnist doesn’t provide sources for her cited figures, but this isn’t a flaw in her reasoning.
E
fails to consider that the severity of injuries to bicyclists from traffic accidents can vary widely
The columnist’s argument is about the factors that contribute to bike-related traffic accidents. The severity of the bicyclists’ injuries from each accident is irrelevant.
A
Most of the people who contract hepatitis E are young adults who were probably exposed to the virus in childhood also.
B
Some laboratory animals exposed to one strain of the hepatitis virus developed immunity to all strains of the virus.
C
Researchers developed a successful vaccine for another strain of hepatitis, hepatitis B, after first isolating the virus that causes it.
D
The virus that causes hepatitis E is very common in some areas, so the number of people exposed to that virus is likely to be quite high in those areas.
E
Many children who are exposed to viruses that cause childhood diseases such as chicken pox never develop those diseases.
Art historian: More than any other genre of representational painting, still-life painting lends itself naturally to art whose goal is the artist’s self-expression, rather than merely the reflection of a preexisting external reality. This is because in still-life painting, the artist invariably chooses, modifies, and arranges the objects to be painted. Thus, the artist has considerably more control over the composition and subject of a still-life painting than over those of a landscape painting or portrait, for example.
Summary
Compared to other kinds of representational painting, still-life painting lends itself more naturally to art whose goal is self-expression. This is because in still-life painting, the artist always chooses, modifies, and arranges the objects to be painted, which gives the artist more control over the composition and subject of the painting than the artist would have with other kinds of representational painting.
Strongly Supported Conclusions
In other kinds of representational painting besides still-life, the artists does not always choose, modify, or arrange the objects to be painted.
The level of control an artist has over the composition and subject of a painting is relevant to whether a style of painting lends itself naturally to self-expression.
A
Landscape painting and portraiture are the artistic genres that lend themselves most naturally to the mere reflection of a preexisting external reality.
Unsupported. We’re not told whether landscape and portraiture lend themselves most to anything. Perhaps there are other kinds of representational painting that lend themselves even more to reflecting preexisting reality.
B
The only way in which artists control the composition and subject of a painting is by choosing, modifying, and arranging the objects to be represented in that painting.
Unsupported. Choosing, modifying, and arranging the objects represented is one way that artists can exercise control, but we’re not told that it’s the only way.
C
Nonrepresentational painting does not lend itself as naturally as still-life painting does to the goal of the artist’s self-expression.
Unsupported. The stimulus doesn’t say anything about nonrepresentational painting. (Landscape and portrait painting are representational.)
D
In genres of representational painting other than still-life painting, the artist does not always choose, modify, and arrange the objects to be painted.
Strongly supported. The fact artists can choose/modify/arrange objects gives the artist more control over a still-life painting than other kinds of representational painting. This implies that in other kinds of repres. painting, the artist doesn’t always choose/modify/arrange.
E
When painting a portrait, artists rarely attempt to express themselves through the choice, modification, or arrangement of the background elements against which the subject of the portrait is painted.
Unsupported. We’re told that in still-life, the artist always chooses/modifies/arranges the objects to be painted. This still allows for the artist to choose/modify/arrange in portrait painting, as long as the artist does not always have the ability to do so.
Food labeling regulation: Food of a type that does not ordinarily contain fat cannot be labeled “nonfat” unless most people mistakenly believe the food ordinarily contains fat. If most people mistakenly believe that a food ordinarily contains fat, the food may be labeled “nonfat” if the label also states that the food ordinarily contains no fat.
Summary
The stimulus can be diagrammed as follows:
Notable Valid Inferences
If most people are aware that a food does not ordinarily contain fat, that food cannot be labeled “nonfat.”
A
Although most people know that bran flakes do not normally contain fat, Lester’s Bran Flakes are not labeled “nonfat.”
Does not violate. The regulation states that, if most people know that bran flakes do not normally contain fat, Lester’s Bran Flakes cannot label their product “nonfat.” Lester’s does not do so and thus is in compliance with this regulation.
B
Although most people are aware that lasagna ordinarily contains fat, Lester’s Lasagna, which contains no fat, is not labeled “nonfat.”
Does not violate. The regulation doesn’t describe situations in which a company must label a product “nonfat,” so Lester’s isn’t in violation by choosing not to do so. Note that “labeled ‘nonfat’” is a sufficient condition, so negating it (as (B) does) cannot yield a violation.
C
Although most garlic baguettes contain fat, Lester’s Garlic Baguettes are labeled “nonfat.”
Does not violate. The entire stimulus and the conditional logic it presents take place in the domain of “food that does not ordinarily contain fat.” This answer choice takes us out of the domain—if garlic baguettes normally contain fat, the regulation has no bearing on them.
D
Although most people are aware that applesauce does not ordinarily contain fat, Lester’s Applesauce is labeled “nonfat.”
Violates the regulation. As shown below, “most people mistakenly believe the food to be fatty” is a necessary condition of “labeled ‘nonfat’”. Since Lester’s Applesauce fails the necessary, it would have to also fail the sufficient in order to comply with the regulation.
E
Although most people mistakenly believe that salsa ordinarily contains fat, the label on Lester’s Zesty Salsa says “This product, like all salsas, is nonfat.”
Does not violate. As long as most people mistakenly believe that a food ordinarily contains fat, a company is allowed to label it “nonfat.” So Lester’s is in compliance with the regulation!