An editor is compiling a textbook containing essays by several different authors. The book will contain essays by Lind, Knight, or Jones, but it will not contain essays by all three. If the textbook contains an essay by Knight, then it will also contain an essay by Jones.

Summary
The stimulus can be diagrammed as follows:

Notable Valid Inferences
If there is an essay by Knight, then there won’t be an essay by Lind.
There can be a maximum of two authors in the textbook.

A
If the textbook contains an essay by Lind, then it will not contain an essay by Knight.
This must be true. As shown in the diagram, Knight and Lind cannot both be included in the textbook. Including Knight means we must also include Jones. This implies that we cannot include Lind, since we cannot include all three authors.
B
The textbook will contain an essay by only one of Lind, Knight, and Jones.
This could be false. It could be the case that two authors are included in the textbook.
C
The textbook will not contain an essay by Knight.
This could be false. The textbook could contain an essay by Knight and Jones.
D
If the textbook contains an essay by Lind, then it will also contain an essay by Jones.
This could be false. The textbook could contain an essay by only Lind.
E
The textbook will contain an essay by Lind.
This could be false. It could be the case that only Knight and Jones are in the textbook.

11 comments

People who object to the proposed hazardous waste storage site by appealing to extremely implausible scenarios in which the site fails to contain the waste safely are overlooking the significant risks associated with delays in moving the waste from its present unsafe location. If we wait to remove the waste until we find a site certain to contain it safely, the waste will remain in its current location for many years, since it is currently impossible to guarantee that any site can meet that criterion. Yet keeping the waste at the current location for that long clearly poses unacceptable risks.

Summary
There are people who argue against the proposed hazardous waste site based on implausible scenarios where the site fails. These people overlook the significant risks associated with delaying moving the waste from its currently unsafe location. If the waste is not moved until a safe site is found, the waste will remain in its current location for years. This is because it's impossible to guarantee that any proposed sight will meet the criteria for being labeled “safe.” Keeping the waste at the current unsafe location for that long presents unacceptable risks.

Strongly Supported Conclusions
The waste should be moved to a new site to reduce risks

A
The waste should never have been stored in its current location.
The stimulus does address past decisions. It is purely concerned with what future actions should be taken.
B
The waste should be placed in the most secure location that can ever be found.
This is antisupported. The stimulus argues against waiting for the most secure location because leaving the waste in the current location presents far too many risks.
C
Moving the waste to the proposed site would reduce the threat posed by the waste.
The stimulus acknowledges that moving the waste is risky, but that it would outweigh the risk of leaving it in its current location. Thus, moving the waste to the proposed site would decrease the overall risk.
D
Whenever waste must be moved, one should limit the amount of time allotted to locating alternative waste storage sites.
This is too broad to support. The stimulus is only concerned with this specific instance and there is no indication that this reasoning should be applicable to “whenever waste must be moved.”
E
Any site to which the waste could be moved will be safer than its present site.
This is too strong to support. The stimulus suggests that the *proposed* site would be safer, not any site whatsoever. What if the waste was dumped on a daycare?

24 comments

A recent survey indicates that the average number of books read annually per capita has declined in each of the last three years. However, it also found that most bookstores reported increased profits during the same period.

"Surprising" Phenomenon
Why have most bookstores reported increased profits in the last three years even though a survey shows the average number of books read annually per person has declined in each of the last three years?

Objective
This is an EXCEPT question. The four wrong answers will tell us something has changed over the past three years that might lead to more bookstore profits despite a decline in average books read.

A
Recent cutbacks in government spending have forced public libraries to purchase fewer popular contemporary novels.
If libraries have fewer popular contemporary novels, more people might be going to bookstores to read those popular novels. This is how bookstore profits might have increased despite a general decline in books read.
B
Due to the installation of sophisticated new antitheft equipment, the recent increase in shoplifting that has hit most retail businesses has left bookstores largely unaffected.
This tells us bookstores haven’t been very affected by a recent spike in shoplifting. But we would still expect bookstore profits to be lower due to the general decline in reading. (B) isn’t giving us a reason to think bookstores could somehow increase their profits.
C
Over the past few years many bookstores have capitalized on the lucrative coffee industry by installing coffee bars.
Bookstores might be making more money from coffee bars today compared to the past. This could explain how bookstore profits could increase despite an overall decline in books read.
D
Bookstore owners reported a general shift away from the sale of inexpensive paperback novels and toward the sale of lucrative hardback books.
Bookstores might be selling more hardback books, which have higher profits margins (”more lucrative”). This could explain how bookstore profits might have increased despite a general decline in books read.
E
Citing a lack of free time, many survey respondents indicated that they had canceled magazine subscriptions in favor of purchasing individual issues at bookstores when time permits.
People might have increased purchases at bookstores in lieu of reading magazines delivered or emailed directly to them from a subscription. This could explain how bookstore profits might have increased despite a general decline in books read.

53 comments

The question stem reads: The reasoning in which of the following is most similar to that in the naturalist's argument? This is a Parallel question.

The naturalist begins by claiming that a species can survive the change in an environment as long as the change is not too rapid. The naturalist has provided a general rule saying that the change can be ok for a species, with the caveat that the change does not occur too rapidly. The naturalist concludes that the threats humans create to woodland species arise not from cutting down trees but from the rate at which we are cutting down trees. The naturalist has applied the universal rule about species to the specific example of woodland species. So the problem is not that change we are creating by cutting down trees, but the because we are causing the change too rapidly.

When evaluating an answer choice, we need a universal rule with a caveat. The correct AC will apply that universal rule to a specific example and say that the specific example is failing to satisfy the caveat.

Answer Choice (A) is incorrect. (A) does not provide a universal rule; it only gives a specific rule about fossil fuels. Additionally, (A) 's rule about fossil fuels lacks the caveat we are looking for.

Answer Choice (B) is incorrect. We can quickly eliminate (B) because of the word "many." Remember, we need a universal rule, so if (B) was right, it would begin with "all people." Additionally, (B) 's rule lacks the caveat we are looking for, nor does (B) apply its rule to a specific example.

Answer Choice (C) is incorrect. Similar to (B), we can eliminate (C) because it says "some" when we are looking for a universal rule. Additionally, (C) also lacks the caveat, nor does (C) apply the rule to a specific example.

Correct Answer Choice (D) matches the stimulus. (D) provides a general rule that "people do not fear change," under the caveat people know what the change will bring. (D) then applies that rule to the specific example of the author's company's employees. The company's employees' fears arise from the fact the company is changing, but because they do not know what the change will bring (the caveat is not satisfied).

Answer Choice (E) is incorrect. (E) does not provide a general rule, so we can eliminate it.


24 comments