ChaseDream

标题: 想不通的一点，请大家指点一下 [打印本页]

作者: 何小媛159753 时间: 2011-8-3 14:42
标题: 想不通的一点，请大家指点一下

A recent report determined that although only three percent of drivers on Maryland highways equipped their vehicles with radar detectors, thirty-three percent of all vehicles ticketed for exceeding the speed limit were equipped with them.Clearly, drivers who equip their vehicles with radar detectors are more likely to exceed the speed limit regularly than are drivers who do not.

The conclusion drawn above depends on which of the following assumptions?

(A) Drivers who equip their vehicles with radar detectors are less likely to be ticketed for exceeding the speed limit than are drivers who do not.

(B) Drivers who are ticketed for exceeding the speed limit are more likely to exceed the speed limit regularly than are drivers who are not ticketed.

(C) The number of vehicles that were ticketed for exceeding the speed limit was greater than the number of vehicles that were equipped with radar detectors.

(D) Many of the vehicles that were ticketed for exceeding the speed limit were ticketed more than once in the time period covered by the report.

(E) Drivers on Maryland highways exceeded the speed limit more often than did drivers on other state highways not covered in the report.

大前提：（通常）装了雷达的人更容易被罚
结论：（所以）装了雷达的人更容易经常超速
条件和结论之间还缺一个小前提（假设）：（因为）被罚的人更容易经常超速（B）
这是刚刚看到的解释，有个疑问： thirty-three percent of all vehicles ticketed for exceeding the speed limit were equipped with them不是说33%的被罚单的人都装有雷达吗？但为什么能说明装了雷达的人更容易被罚呢，不是还有67%的的被罚的人没有装雷达吗？

不知道哪里想错了？

作者: balapupu 时间: 2011-8-3 14:50
注意大前提，全市人口中只有3％的人装了雷达，所以按照正常的推测，也应该是3％的人超速，但是现在被罚超速的人有33％，所以装了容易被罚，而且被罚的人更容易超速。

作者: balapupu 时间: 2011-8-3 14:52
第四话表达错了，应该是被罚的人有3％装了雷达。

欢迎光临 ChaseDream (https://forum.chasedream.com/)