CXD page 41 question 15

lifenlifenlifen

15

In 1985 a consumer agency concluded that Xylo brand bicycle are safer to ride than are Zenon brand bicycles. The agency based the conclusion on the ratio of the number of rider injuries to the number of riding hours for each brand of bicycle from 1981 through 1984. Yet for identically designed bicycles manufactured since 1985, the number of rider injuries has been twice as great among riders of Xylos as among riders of Zenons. Therefore, the agency’s conclusion would have been different for the period since 1985.

Which of the following is an assumption that, if true, supports the claim that the agency’s conclusion would have been different for the period since 1985?

(A)         For the period since 1985, the number of riding hours for Zenons totaled at least half the number of riding hours for Xylos.

(B)         Of all the bicycles ridden in the period since 1985, the percentage of Xylos ridden was twice the percentage of Zenons ridden.

(C)         Prior to 1985, Zenon owners were more likely than Xylo owners to report the injuries they sustained while riding their bicycles.

(D)         In 1985 the agency had miscalculated the ratio for Xylos, for Zenons, or for both.

(E)                Soon after the agency had issued its report, consumer demand for Xylos increased more rapidly than did consumer demand for Zenons.

Choice A is the best answer.

If by eliminating, i will choose A too. But I just can't quite get the logic behind it. Please explain.

And in dealing with such questions as this one (questions have actual numbers, ratio), do I really have to calcuate to get the answer? Or I am thinking too complicate?

thank you!!

[此贴子已经被作者于2004-8-26 2:51:30编辑过]

lawyer_1

81-84比较的是RATIO（比率：the ratio of the number of rider injuries to the number of riding hours ），since85，比较的是the number of rider injuries 。忽略的因素为时间，A说的正是时间因素。

matthewfs

列出不等式,衡量之后的变化,保持不等式符号不变