请教大神一道狒狒逻辑上的题目

378592285 · 发表于 2015-7-1 21:57:25

When 100 people who have not used cocaine are tested for cocaine use, on average only 5 will test positive. By contrast, of every 100 people who have used cocaine 99 will test positive. Thus, when a randomly chosen group of people is tested for cocaine use, the vast people is tested for cocaine use, the vast majority of those who test positive will be people who have used cocaine.
A reasoning error in the argument is that the argument
(A) attempts to infer a value judgement from purely factual premises
(B) attributes to every member of the population the properties of the average member of the population
(C) fails to take into account what proportion of the population have used cocaine
(D) ignores the fact that some cocaine users do not test positive
(E) advocates testing people for cocaine use when there is no reason to suspect that they have used cocaine

就是想问B选项什么意思，还有这道题选什么呢？？谢谢~~~

378592285 · 发表于 2015-7-2 16:17:34

DDDD

alzn2765 · 发表于 2015-8-6 12:11:33

C

这就是一道无聊的数学题：
如果总人口是10000（包括吸毒了的和没吸毒的），根据test的误测特点，会有500个没吸毒的人被误测为吸毒了。可如果这10000人中只有100个吸毒的呢？这100个人中会有99个被测出来。
现在有500个冤枉的和99个死有余辜的，那个多？

请教大神一道狒狒逻辑上的题目

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