Documentary videotapes always provide useful information, but only those videotapes that hold the interest of students are worth showing in school. Some documentaries are boring.
Which one of the following conclusions can be properly drawn from the passage??
Some videotapes which provide useful information are not worth showing in school.
All videotapes that are boring provide useful information.
Some videotapes that are worth showing in school are boring.
Some documentaries that hold the interest of students are not worth showing in school.
No videotape that holds the interest of students is worth showing unless it provides useful information.
Firous, a flame-resistant insulator used in the smelting process, causes brain tumors in rats, but only when the rats are exposed to large quantities of its fibrous dust. To inhale a quantity of fibrous dust equivalent to that inhaled by the rats in studies, a smelter would have to work near the insulator for 18 hours a day. Therefore it is safe to use Firous in smelting.
In order for the conclusion that Firous is safe to use in smelting to be properly drawn, which one of the following must be true?
Brain tumors from exposure to airborne substances develop more quickly in people than they do in rats.
If all insulators that are used in smelting were tested, researchers would discover that some cause brain tumors in rats.
Smelters work near Firous insulation fewer than 18 hours a day.
Smelters are less likely to incur severe burn injuries when Firous is used in the smelting process.
Some of the research done on Firous did not pertain to the issue of whether Firous causes brain tumors in humans.
A computer industry newsletter recently claimed that if the price of computer logic chips is reduced by 40 percent, the retail price for computer systems which utilize these chips will undergo the same decrease in price.
Which of the following would a skeptic most likely point out about the computer newsletter's claim?
Advances in computer engineering now allow computer designers to achieve the same level of computing power while using a fewer number of computer logic chips.
Owners of computer retail stores will not increase their profit margins.
The computer industry is an especially competitive field in which firms vying for business keep computer prices low.
Research indicates that the number of computer systems purchased increases substantially after the retail price is reduced more than 30 percent.
Advertising costs, marketing expenses and handling fees, none of which are linked to the price of computer chips, make up a substantial portion of the retail price of computer systems.
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