Many breakfast cereals are fortified with vitamin supplements. Some of these cereals provide 100 percent of the recommended daily requirement of vitamins. Nevertheless, a well-balanced breakfast’ including a variety of foods, is a better source of those vitamins that are such fortified breakfast cereals alone.

Which of the following, if true, would most strongly support the position above?

A famous singer recently won a lawsuit against an advertising firm for using another singer in a commercial to evoke the famous singer’s well-known rendition of a certain song. As a result of the lawsuit, advertising firms will stop using imitators in commercials. Therefore, advertising costs will rise, since famous singers’services cost more than those of their imitators.

The conclusion above is based on which of the following assumptions?

A group of children of various ages was read stories in which people caused harm, some of those people doing so intentionally and some accidentally. When asked about appropriate punishments for those who had caused harm, the younger children, unlike the older ones, assigned punishments that did not vary according to whether the harm was done intentionally or accidentally. Younger children, then, do not regard people’s intentions as relevant to punishment.

Which of the following, if true, would most seriously weaken the conclusion above?

The program to control the entry of illegal drugs into the country was a failure in 1987. If the program had been successful, the wholesale price of most illegal drugs would not have dropped substantially in 1987.

The argument in the passage depends on which of the following assumptions?

Many institutions of higher education suffer declining enrollments during periods of economic slowdown. At two-year community colleges, however, enrollment figures boom during these periods when many people have less money and there is more competition for jobs.

Each of the following, if true, helps to explain the enrollment increases in two’year community colleges described above EXCEPT:

Hardin argued that grazing land held in common (that is, open to any user) would always be used less carefully than private grazing land. Each rancher would be tempted to overuse common land because the benefits would accrue to the individual, while the costs of reduced land quality that results from overuse would be spread among all users. But a study comparing 217 million acres of common grazing land with 433 million acres of private grazing land showed that the common land was in better condition.

The answer to which of the following questions would be most useful in evaluating the significance, in relation to Hardin’s claim, of the study described above?

In tests for pironoma, a serious disease, a false positive result indicates that people have pironoma when, in fact, they do not; a false negative result indicates that people do not have pironoma when’ in fact’ they do. To detect pironoma most accurately, physicians should use the laboratory test that has the lowest proportion of false positive results.

Which of the following, if true, gives the most support to the recommendation above?

In many corporations, employees are being replaced by automated equipment in order to save money. However, many workers who lose their jobs to automation will need government assistance to survive, and the same corporations that are laying people off will eventually pay for that assistance through increased taxes and unemployment insurance payments.

The author is arguing that

According to the new office smoking regulations, only employees who have enclosed offices may smoke at their desks. Virtually all employees with enclosed offices are at the professional level, and virtually all secretarial employees lack enclosed offices. Therefore, secretaries who smoke should be offered enclosed offices.

Which of the following is an assumption that enables the conclusion above to be properly drawn?

The difficulty with the proposed high-speed train line is that a used plane can be bought for one-third the price of the train line, and the plane, which is just as fast, can fly anywhere. The train would be a fixed linear system, and we live in a world that is spreading out in all directions and in which consumers choose the free-wheel systems (cars, buses, aircraft), which do not have fixed routes. Thus a sufficient market for the train will not exist.

Which of the following, if true, most severely weakens the argument presented above?