Summarize Argument
The author concludes the lottery didn’t give all entrants an equal chance of winning. Why not? Because 90 percent of the people who won had entered within the first 2 days of the registration period, which was 30 days long.
Notable Assumptions
The author assumes the lottery gave early entrants a more-than-even chance of winning, and that’s why most people who won had entered early. In particular, this means assuming that significantly fewer than 90 percent of the total entries were submitted within the first 2 days.
A
The family members of the organizer of the contest were not permitted to participate in the contest.
This is irrelevant. It makes no claim about the timing of lottery entries or the selection process. If anything, it suggests the lottery is more likely to have been fair, not less.
B
The manner in which the contest winner would be selected was publicized prior to the selection of the winner.
This is irrelevant. It doesn’t say that method gave any early entrants a higher chance of winning.
C
The contest entry forms were submitted at a consistent rate throughout the registration period.
This makes concrete the author’s primary assumption: that fewer than 90 percent of the total entries were submitted in the first two days. It makes it less likely that pure chance caused most of the winners to be early entrants.
D
The rules of the contest were posted conspicuously by those who organized the contest.
This is irrelevant. It doesn’t say those rules gave early entrants a better chance of winning than late entrants.
E
The number of people entering the contest far exceeded the expectations of the contest organizers.
This is irrelevant. It doesn’t imply the lottery organizers selected winners before the contest ended, or that they gave early entrants a better chance of winning.
Summarize Argument: Phenomenon-Hypothesis
The author hypothesizes that playing a musical instrument alters brain structure. As evidence, he notes that the part of the brain responsible for differentiating piano sounds tends to be larger in highly skilled musicians than in people who rarely play an instrument.
Identify and Describe Flaw
This is the cookie-cutter flaw of assuming that correlation proves causation. The author points out a correlation: a certain area of the brain tends to be larger in highly skilled musicians. He then jumps to the conclusion that playing an instrument causes changes to the brain. He overlooks two key alternative hypotheses:
(1) The causal relationship could be reversed— maybe having a larger brain area causally contributes to people becoming highly skilled musicians.
(2) Maybe there’s some other, underlying factor that causes both altered brain structure and musical skill.
A
The argument presumes, without providing justification, that what is true about the brain structures of highly skilled pianists is also true of the brain structures of other highly skilled musicians.
The author only says that a certain area of the brain tends to be larger in highly skilled musicians. Presumably this correlation also applies to highly skilled pianists, but he never specifically mentions the brain structure of pianists.
B
The argument fails to address the possibility that people who become highly skilled musicians do so, in part, because of the size of a certain area of their brains.
The author overlooks the possibility that the causal relationship could be reversed. Maybe having a larger brain area causally contributes to people becoming highly skilled musicians, not the other way around.
C
The argument draws a conclusion about a broad range of phenomena from evidence concerning a much narrower range of phenomena.
This is the cookie-cutter flaw of hasty generalization, where the argument draws a broad conclusion from too little evidence. The author doesn’t make this mistake. He draws a conclusion about musicians’ brain structures from evidence about musicians’ brain structures.
D
The argument fails to address the possibility that a certain area of the brain is smaller in people who have listened to a lot of music but who have never learned to play a musical instrument than it is in people who have learned to play a musical instrument.
The author does address this possibility. He explicitly says that a certain area of the brain is smaller in non-musicians than in highly skilled musicians. The amount of music that people listen to is irrelevant.
E
The argument presumes, without providing justification, that highly skilled musicians practice more than other musicians.
The author never makes this assumption. He compares the brain structures of highly skilled musicians and non-musicians (people who “rarely, if ever,” play an instrument). He doesn’t compare highly skilled musicians to other musicians.
Summary
The author concludes that the journalist will reveal the informant’s identity. This is based on the following:
If she is ordered to do so by a judge or by her editor, the journalist will publicly reveal the informant’s identity.
The information provided by the informant concerns safey violations at the power plant.
If she is ordered to do so by a judge or by her editor, the journalist will publicly reveal the informant’s identity.
The information provided by the informant concerns safey violations at the power plant.
Missing Connection
We know what is sufficient to infer that the journalist will publicly reveal the identity — a judge or her editor orders her to. Do we have enough to establish that a judge or her editor will order her to reveal the identity? No. But we do know that the information concerns safety violations. If we can get from the fact that the information concerns safety violations to the idea that a judge or her editor will order her to disclose, that would make the argument valid.
A
The information that the informant provided is known to be false.
(A) doesn’t establish that a judge or her editor will order disclosure. So it doesn’t trigger the premise concerning when the journalist will reveal the informant’s identity.
B
The journalist’s editor will not order her to reveal the informant’s identity unless the information is accurate and concerns public safety.
(B) tells us that if the information is not accurate or does not concern public safety, then the editor will NOT order disclosure. But we’re trying to prove that the judge or editor WILL order disclosure.
C
If the information concerns safety at the power plant, a judge will order the journalist to reveal her informant’s identity.
We know that the information concerns safety at the power plant. Based on (C), we can infer, then, that the judge will order disclosure of the identity. Based on the first premise, then, we can conclude that the journalist will reveal the informant’s identity.
D
The truth of the information provided by the informant can be verified only if the informant’s identity is publicly revealed.
(D) doesn’t establish that a judge or her editor will order disclosure. So it doesn’t trigger the premise concerning when the journalist will reveal the informant’s identity.
E
The informant understood, at the time the journalist promised him confidentiality, that she would break this promise if ordered to do so by a judge.
(E) doesn’t establish that a judge or her editor will order disclosure. So it doesn’t trigger the premise concerning when the journalist will reveal the informant’s identity.
Summarize Argument
The pundit concludes that it’s a good thing to vote out national leaders every few years because reforms are usually undertaken early in an administration. If a government doesn’t make those reforms early on, they’ll be forced to either admit a mistake, deny a problem, or abrogate responsibility later on.
Identify Conclusion
The conclusion is about the value of voting out leaders: “It is good to have national leaders voted out of office after a few years.”
A
If national leaders who fail to solve problems are voted out of office after a few years, new leaders will be more motivated to solve problems.
This doesn’t appear in the pundit’s argument and therefore can’t be the main conclusion. We don’t know if new leaders will be more motivated to solve problems when national leaders are voted out.
B
National leaders who stay in power too long tend to deny responsibility for problems that they could have dealt with earlier.
This is a premise that the pundit uses to show why it’s good to vote national leaders out every few years. If the leaders simply deny responsibility for problems, they won’t solve them. This is why new leaders are a good thing.
C
National leaders are most likely to undertake reforms early in a new government.
This is a premise that the pundit uses to show why voting out national leaders is a good thing. Once a government has been around for a while and made their initial reforms, they have limited options for reforms down the road.
D
National leaders who immediately respond to problems upon taking office should be given enough time to succeed at solving them.
This doesn’t appear in the pundit’s argument and thus can’t be a main conclusion. The pundit isn’t arguing about how much time governments should be given, but rather what voters should do every few years.
E
National leaders should be removed from office every few years by the voting in of new leaders.
The pundit argues that it’s a good thing to vote out national leaders every year so that new ones can replace them and make the reforms an incumbent government is less likely to make. The pundit’s stance that “it is good” is equivalent here to “should,” since both are recommending a course of action.
Summary
The author concludes that stiff competition can undermine employee performance. This is based on the fact that if one competitor is perceived to be clearly superior, other competitors become anxious and doubt their own ability to perform.
Missing Connection
The conclusion asserts that competition can hurt employee performance. But the premise establishes only that competition might lead to other competitors becoming anxious and having self-doubt about their performance. Do these feelings actually undermine performance? We have no reason to think so. Maybe those feelings actually spur people to perform better? To make the argument valid, we want to establish that feelings of anxiety or self-doubt about one’s ability to perform undermine employee performance.
A
Those who are perceived to be clearly superior almost always win.
(A) doesn’t establish anything about what undermines employee performance. Since neither this answer nor the premise establishes that something undermines employee performance, it cannot make the argument valid.
B
The winner of a competition is often the competitor who exerts the most effort.
(B) doesn’t establish anything about what undermines employee performance. Since neither this answer nor the premise establishes that something undermines employee performance, it cannot make the argument valid.
C
When competitors perceive the competition as winnable, their overall performance generally improves.
(C) doesn’t establish anything about what undermines employee performance. Since neither this answer nor the premise establishes that something undermines employee performance, it cannot make the argument valid. In addition, (C) tells us what improves performance. We’re trying to conclude that something hurts performance.
D
Doubting one’s own ability to perform can decrease one’s overall performance.
(D) connects doubting one’s own ability to perform to undermining employee performance. If (D) is true, stiff competition, because it can lead to self-doubt about ability to perform, hurts employee performance.
E
Competitors who work to undermine the confidence of other participants often do better in competitions.
(E) doesn’t establish anything about what undermines employee performance. Since neither this answer nor the premise establishes that something undermines employee performance, it cannot make the argument valid.