请教: GMAT CR真题 S9-16

jq_jou

16. 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.

正确的答案是B), 记得曾经有人说过A)错在推翻了原文的PREMISE, 因为原文中明显表明Drivers who equip their vehicles with radar detectors are more likely to be ticketed.
个人认为: A)错在没有regularly 这个词, 如果有了, 那么一定也是正确选项. 因为很有可能EQUIP RADAR DETECTOR的DRIVER超速的比例远远大于被捉的33%. 这算是推翻了原文的PREMISE吗?

dorbear

这是一个论据保持型假设，文中从一种现象推出一个调查结论；但要使结论保持，必须保证这种现象不是偶然。

为什么会考虑(A)　呢？有无 Regularly是一样的，它没有否定任何前提或结论呀？

fyhllj

以下是引用dorbear在2003-9-29 6:10:00的发言：
这是一个论据保持型假设，文中从一种现象推出一个调查结论；但要使结论保持，必须保证这种现象不是偶然。

为什么会考虑(A)　呢？有无 Regularly是一样的，它没有否定任何前提或结论呀？

同意dorbear的解释

有无 Regularly是一样的

jq_jou

我的想法如下:
如果把A)取非:  Drivers who equip their vehicles with radar detectors are MORE likely to be ticketed for exceeding the speed limit than are drivers who do not.

那么原文的结论: drivers who equip their vehicles with radar detectors are more likely to EXCEED the speed limit ... 就不成立了. 因为可能33%是由于他们装了RADAR,所以比较容易被捉到而且被TICKETED. 没有装RADAR的可能超速的超过33%, 但是只有3%的被抓到被TICKETED. 不是说红色的CAR超速普遍容易被捉到吗?
这种分析有什么漏洞?  我发现这方面的确比较弱,  帮我分析一下错误的地方.

dorbear

如果用取反方法来做假设题，取反后使原文完全不成立的才是假设。
(A) 取反后有一定削弱作用（比例高的原因有可能是因为容易被抓住，但只是可能），但并不能完全否定原文。

遗失的紫水晶

论据：3%的车装有雷达，33%被ticketed 的车装有雷达==》结论：装有雷达的的车的人比不装的人更有可能超速
我觉得如果要用取反做题：
A ：Drivers who equip their vehicles with radar detectors are not less likely to be ticketed for exceeding the speed limit than are drivers who do not.
 
说明：装有雷达的车的司机并没有比不装雷达的车的司机被ticketed 的可能性小（意思是：ticketed 的可能性可能多或一样 ，注意有可能“一样”，所以并不能推翻原假设）

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

说明：被ticketed 的司机超速的可能性并没有没有被ticketed 的司机多（意思是：可能性一样或者更少，直接加深了原文的gap，推翻了原文）
 所以这种题取非不能直接把less变成more 或more 变成less，这样会少掉条件，应给直接加not）

不知这样想对不对，请指教

遗失的紫水晶

再啰嗦一下，A选项经过这样取非，就不能像lz 说的那样驳掉原问了，因为可能性高只是一方，还有可能一样啊~~而B选项取非后，不管可能性是相等还是小原文都推不出结论了。

还请哪位大N 看看我这样想对不对啊！