一道OG CR题，之前没有人问过同个选项

典座

In Wareland last year, 16 percent of licensed drivers under 21 and 11 percent of drivers ages 21–24 were in serious accidents. By contrast, only 3 percent of licensed drivers 65 and older were involved in serious accidents. These figures clearly show that the greater experience and developed habits of caution possessed by drivers in the 65-and-older group make them far safer behind the wheel than the younger drivers are.

Which of the following is an assumption on which the argument depends?

A. Drivers 65 and older do not, on average, drive very many fewer miles per year than drivers 24 and younger.

B. Drivers 65 and older do not constitute a significantly larger percentage of licensed drivers in Wareland than drivers ages 18–24 do.

C. Drivers 65 and older are less likely than are drivers 24 and younger to drive during weather conditions that greatly increase the risk of accidents.

D. The difference between the accident rate of drivers under 21 and of those ages 21–24 is attributable to the greater driving experience of those in the older group.

E. There is no age bracket for which the accident rate is lower than it is for licensed drivers 65 and older.

我错选了B。

说一下我的想法——读完题干我就先猜想了两个填补gap的备选：1.年轻人和老人样本人数相同且大量；2.年轻人不会比老人开车更多。

A和B之间犹豫了一下就选了B。

后来再读B，发现对比的是18-24区间的人，而文中只24岁以下的年轻人，和A区间重合。那么，如果B也换成和A一样的区间，B是不是就也对了？（这是偷懒技巧吗？）

按正常推理，B符合猜想1，A符合猜想2，我不知道B还有哪里不对...........

先谢谢各路大侠啦。

典座

补充：我看到之前有一个帖子说B是无关选项，但是我第一个想到的就是样本的size要基本相同，这不是最基本的吗.......
试想：如果老人只找了10人，他们正好都没出过车祸，年轻人找了500人，出车祸了10多起，那也是老年团胜利啊。我有点钻进死胡同了..........

小小豆豆酱

为什么需要老年人和年轻人样本数量相同?这里本来就是percentage了啊？
样本数量是否相同对于结论没有影响

典座

小小豆豆酱 发表于 2020-5-6 11:50
为什么需要老年人和年轻人样本数量相同?这里本来就是percentage了啊？
样本数量是否相同对于结论没有影响 ...

谢谢啊