ChaseDream

标题: 请教一道OG里的题 [打印本页]

作者: mumuceiber 时间: 2010-7-22 17:40
标题: 请教一道OG里的题

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.
key=B
不太明白B的思路，为甚么A不对呢？大家帮忙指点下吧~~~~

作者: Jessielynn 时间: 2010-7-22 19:13
前提是33%的vehicles ticketed for exceeding the speed limit 是装这个雷达的，结论是装雷达的车更容易exceed the speed limit regularly
前提和结论之间有个断层，就是要把ticketed for exceeding和exceed the speed limit regularly联系起来，即答案B，ticketed for exceeding的人倾向于exceed the speed limit regularly

不知道我讲清楚了没。。。

作者: mumuceiber 时间: 2010-7-23 11:38
是不是就是说被开罚单不一定就等于超速，所以要在两者间建立起联系，即ticketed for exceeding的人倾向于exceed the speed limit regularly
我对A的想法是，前面说3%装雷达，33%被开罚单的vehicles装了雷达，有可能是因为装了雷达所以导致更容易被开罚单，所以A说装了雷达更不容易被开罚单，而还有33%装雷达的被开了单，所以更容易超速。
是不是如果这么想的话还差了一步B的推导，而且应该找因果之间的断层而不是在原因或结果里找？？？

作者: Jessielynn 时间: 2010-7-24 12:11

是不是就是说被开罚单不一定就等于超速，所以要在两者间建立起联系，即ticketed for exceeding的人倾向于exceed the speed limit regularly
我对A的想法是，前面说3%装雷达，33%被开罚单的vehicles装了雷达，有可能是因为装了雷达所以导致更容易被开罚单，

-- by 会员 mumuceiber (2010/7/23 11:38:38)

你的思路到这里都是对的，装了雷达更容易被开罚单，但是结论说的是装了雷达更容易习惯性超速，显然和前提有断层了，断层就是前提里的“容易被开罚单”和结论里的新信息“习惯性超速”之间的联系

作者: SAGA5 时间: 2010-7-28 21:17
我整理一下（用元素ABC表示） A是装雷达 B是被罚 C是超速 MORE LIKELY就是方向

题目条件得出：A到B （A装雷达易B被罚）
只有当：B到C ( B被罚者易C超速)--正确答案
才可以得出结论：A到C （A装雷达易C超速）

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