OG11-77

angela7258

Questions 76-77 are based on the following.

Roland: The alarming fact is that 90 percent of the people in this country now report that they know someone who is unemployed.

Sharon: But a normal, moderate level of unemployment is 5 percent, with 1 out of 20 workers unemployed. So at any given time if a person knows approximately 50 workers, 1 or more will very likely be unemployed.

77 Sharon's argument relies on the assumption that

(A) normal levels of unemployment are rarely exceeded

(B) unemployment is not normally concentrated in geographically isolated segments of the population

(C) the number of people who each know someone who is unemployed is always higher than 90% of the population

(D) Roland is not consciously distorting the statistics he presents

(E) knowledge that a personal acquaintance is unemployed generates more fear of losing one's job than does knowledge of unemployment statistics

没看懂，看了解释和以前的讨论还是没懂。1/50 = 2%， 和90% 或5% 有什么关系呢？

scicdavid

R说：90%的人说身边有人是失业的。 S说：失业率是5%，也就是20个人里面就会有1个人事业。如果一个人认识50个人，那么他所认识的50个人里面就有1个或者更多的人是失业的。（因为按他说的比例20个人里面有1个，那么50个人应该有2.5个人失业，只要A先生认识的50个人里面有1个人失业，那么，A先生就会说身边有人失业。这50个人里的B先生，C先生等等（98%=1-2%）的人都会说身边有人失业。但是实际上只有1个人失业。

angela7258

感谢LS的解释，清楚多了，我当时选的是A就很明显的错误了。但是这道题还是很容易和C选项争议。问题是不是出在C选项"always"这个词上呢？

另外，曾见到有人指出assumption题应该首先看选项中有not的，在考试中是否成立呢？