请教prep2-40

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.

 这道题困扰我巨长时间了, 不知思路在那里.恳请牛牛们帮我一下呀!

簡單的來說
                             觀察: 被開罰單的人(A)= 裝測速器的人(B)  而結論是裝測速器(B)=愛超速(C)  

要如何推論出(B)=(C)呢?  前提就是被開罰單的人(A)=愛超速(C)

 (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.(X)

(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.(被開罰單的人比沒被開罰單的人容易超速)

(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.(X)

(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.(X)

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

很明显2楼的思路不对。

B选项若成立，即被Ticketed的Driver比没被Ticketed的more likely to exceed 。

可得到：无论装没装radar detectors，Ticketed的Driver都更喜欢超速，换句话说，即没装radar detectors但被Ticketed的Driver也更喜欢超速。两者喜欢超速的程度是一致的。

结论：被Ticketed的number里面，装radar detectors的比例应该还接近3%啊。

这明显与题目中的信息矛盾。

请牛人解答！！

呵呵，“测速器”翻译的不够准确。

中国人平常俗称“电子狗”。如果还不知道是什么东西，请百度一下。

顶一个,讲的非常精彩

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