CR - Assumptions: Get your knives out!

CR - Assumptions: Get your knives out!

1. Until now, only injectable vaccines against influenza have been available. Parents are reluctant to subject children to the pain of injections, but adults, who are at risk of serious complications from influenza, are commonly vaccinated. A new influenza vaccine, administered painlessly in a nasal spray, is effective for children. However, since children seldom develop serious complications from influenza, no significant public health benefit would result from widespread vaccination of children using the nasal spray. Which of the following is an assumption on which the argument depends?

A. Any person who has received the injectable vaccine can safely receive the nasal-spray vaccine as well.
B. The new vaccine uses the same mechanism to ward off influenza as injectable vaccines do.
C. The injectable vaccine is affordable for all adults.
D. Adults do not contract influenza primarily from children who have influenza.
E. The nasal spray vaccine is not effective when administered to adults.


2. Last year all refuse collected by Shelbyville city services was incinerated. This incineration generated a large quantity of residue ash. In order to reduce the amount of residue ash Shelbyville generates this year to half of last year’s total, the city has revamped its collection program. This year city services will separate for recycling enough refuse to reduce the number of truckloads of refuse to be incinerated to half of last year’s number. Which of the following is required for the revamped collection program to achieve its aim?

A. This year, no materials that city services could separate for recycling will be incinerated.
B. Separating recyclable materials from materials to be incinerated will cost Shelbyville less than half what it cost last year to dispose of the residue ash.
C. Refuse collected by city services will contain a larger proportion of recyclable materials this year than it did last year.
D. The refuse incinerated this year will generate no more residue ash per truckload incinerated than did the refuse incinerated last year.
E. The total quantity of refuse collected by Shelbyville city services this year will be no greater than that collected last year.


3. Newspaper editorial: In an attempt to reduce the crime rate, the governor is getting tough on criminals and making prison conditions harsher. Part of this effort has been to deny inmates the access they formerly had to college-level courses. However, this action is clearly counter to the governor’s ultimate goal, since after being released from prison, inmates who had taken such courses committed far fewer crimes overall than other inmates. Which of the following is an assumption on which the argument depends?

A. Not being able to take college-level courses while in prison is unlikely to deter anyone from a crime that he or she might otherwise have committed.
B. Former inmates are no more likely to commit crimes than are members of the general population.
C. The group of inmates who chose to take college-level courses were not already less likely than other inmates to commit crimes after being released.
D. Taking high school level courses in prison has less effect on an inmate’s subsequent behavior than taking college-level courses does.
E. The governor’s ultimate goal actually is to gain popularity by convincing people that something effective is being done about crime.


4. Two centuries ago, Tufe Peninsula became separated form the mainland, isolating on the newly formed Tufe Island a population of Turfil sunflowers. This population’s descendants grow to be, on average, 40 centimeters shorter than Turfil sunflowers found on the mainland. Tufe Island is significantly drier than Tufe Peninsula was. So the current average height of Tufe’s Turfil sunflowers is undoubtedly at least partially attributable to changes in Tufe’s environmental conditions. Which of the following is an assumption on which the argument depends?

A. There are no types of vegetation on Tufe Island that are known to benefit from dry conditions.
B. There were about as many Turfil sunflowers on Tufe Peninsula two centuries ago as there are on Tufe Island today.
C. The mainland’s environment has not changed in ways that have resulted in Turfil sunflowers on the mainland growing to be 40 centimeters taller than they did two centuries ago.
D. The soil on Tufe Island, unlike that on the mainland, lacks important nutrients that help Turfil sunflowers survive and grow tall in a dry environment.
E. The 40-centimeter height difference between the Turfil sunflowers on Tufe Island and those on the mainland is the only difference between the two populations.


5. The average hourly wage of television assemblers in Vernland has long been significantly lower than that in neighboring Borodia. Since Borodia dropped all tariffs on Vernlandian televisions three years ago, the number of televisions sold annually in Borodia has not changed. However, recent statistics show a droip in the number of television assemblers in Borodia. Therefore, updated trade statistics will probably indicate that the number of televisions Borodia imports annually from Vernland has increased. Which of the following is an assumption on which the argument depends?

A. The number of television assemblers in Vernland has increased by at least as much as the number of television assemblers in Borodia has decreased.
B. Televisions assembled in Vernland have features that televisions assembled in Borodia do not have.
C. The average number of hours it takes a Borodian television assembler to assemble a television has not decreased significantly during the past three years.
D. The number of televisions assembled annually in Vernland has increased significantly during the past three years.
E. The difference between the hourly wage of television assemblers in Vernland and the hourly wage of television assemblers in Borodia is likely to decrease in the next few years.


6. In Teruvia, the quantity of rice produced per year is currently just large enough to satisfy domestic demand. Teruvia’s total rice acreage will not be expanded in the foreseeable future, nor will rice yields per acre increase appreciably. Teruvia’s population, however, will be increasing significantly for years to come. Clearly, therefore, Teruvia will soon have to begin importing rice.

Which of the following is an assumption on which the argument depends?

A. No pronounced trend of decreasing per capita demand for rice is imminent in Teruvia.
B. Not all of the acreage in Teruvia currently planted with rice is well suited to the cultivation of rice.
C. None of the strains of rice grown in Teruvia are exceptionally high-yielding.
D. There are no populated regions in Teruvia in which the population will not increase.
E. There are no major crops other than rice for which domestic production and domestic demand are currently in balance in Teruvia.


7. In the past the country of Siduria has relied heavily on imported oil. Siduria recently implemented a program to convert heating systems from oil to natural gas. Siduria already produces more natural gas each year than it burns, and oil production in Sidurian oil fields is increasing at a steady pace. If these trends in fuel production and usage continue, therefore, Sidurian reliance on foreign sources for fuel should decline soon. Which of the following is an assumption on which the argument depends?

A. In Siduria the rate of fuel consumption is rising no more quickly than the rate of fuel production.
B. Domestic production of natural gas is rising faster than is domestic production of oil in Siduria.
C. No fuel other than natural gas is expected to be used as a replacement for oil in Siduria.
D. Buildings cannot be heated by solar energy rather than by oil or natural gas.
E. All new homes that are being built will have natural-gas-burning heating systems.


8. Three large companies and seven small companies currently manufacture a product with potential military applications. If the government regulates the industry, it will institute a single set of manufacturing specifications to which all ten companies will have to adhere. In this case, therefore, since none of the seven small companies can afford to convert their production lines to a new set of manufacturing specifications, only the three large companies will be able to remain in business. Which of the following is an assumption on which the author’s argument relies?

A. None of the three large companies will go out of business if the government does not regulate the manufacture of the product.
B. It would cost more to convert the production lines of the small companies to a new set of manufacturing specifications than it would to convert the production lines of the large companies.
C. Industry lobbyists will be unable to dissuade the government from regulating the industry.
D. Assembly of the product produced according to government manufacturing specifications would be more complex than current assembly procedures.
E. None of the seven small companies currently manufactures the product to a set of specifications that would match those the government would institute if the industry were to be regulated.


9. Exposure to certain chemicals commonly used in elementary schools as cleaners or pesticides causes allergic reactions in some children. Elementary school nurses in Renston report that the proportion of schoolchildren sent to them for treatment of allergic reactions to those chemicals has increased significantly over the past ten years. Therefore, either Renston’s schoolchildren have been exposed to greater quantities of the chemicals, or they are more sensitive to them than schoolchildren were ten years ago. Which of the following is an assumption on which the argument depends?

A. The number of school nurses employed by Renston’s elementary schools has not decreased over the past ten years.
B. Children who are allergic to the chemicals are no more likely than other children to have allergies to other substances.
C. Children who have allergic reactions to the chemicals are not more likely to be sent to a school nurse now than they were ten years ago.
D. The chemicals are not commonly used as cleaners or pesticides in houses and apartment buildings in Renston.
E. Children attending elementary school do not make up a larger proportion of Renston’s population now than they did ten years ago.


10. A significant number of complex repair jobs carried out by Ace Repairs have to be reworked under the company’s warranty. The reworked jobs are invariably satisfactory. When initial repairs are inadequate, therefore, it is not because the mechanics lack competence; rather, there is clearly a level of focused concentration that complex repairs require that is elicited more reliably by rework jobs than by first-time jobs. The argument above assumes which of the following?

A. There is no systematic difference in membership between the group of mechanics who do first-time jobs and the group of those who do rework jobs.
B. There is no company that successfully competes with Ace Repairs for complex repair jobs.
C. Ace Repairs’ warranty is good on first-time jobs but does not cover rework jobs.
D. Ace Repairs does not in any way penalize mechanics who have worked on complex repair jobs that later had to be reworked.
E. There is no category of repair jobs in which Ace Repairs invariably carries out first-time jobs satisfactorily.