求教老prep 58题

pandrew

58.   (34705-!-item-!-188;#058&007581)

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

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

Sharon's argument relies on theassumption that

(A) normal levels of unemploymentare rarely exceeded

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

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

(D) Roland is not consciouslydistorting the statistics he presents

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

正确答案选B， 但是这个跟geographically有什么关系呢？并没有从S的论证中看出这个assumption.求NN指教！！

pandrew

tophoenix 发表于 2015-5-9 23:26
这么理解
如果每20人，就有一个失业，那么，每50人，就有2.5个失业的。2.5 〉1。　所以，一定有失业的　 ...

谢谢啦~似乎明白很多了

pandrew

tophoenix 发表于 2015-5-7 20:23
如果那些失业的都呆在一起， 就有人会发现周围有大量的失业比例。 所以，原题不成立。
因此，选Ｂ ...

谢谢您的解答，B的逻辑是没问题，但是我不明白S的argument到底说明了一个什么结论呢？“So at any given time if a person knows approximately 50 workers, 1 or more will very likely be unemployed." 1/20大于比1/50，也就是normal rate更大? 但S的目的不是要说normal rate比R假设的rate小吗? 谢谢！

pandrew

谢谢您的解答，B的逻辑是没问题，但是我不明白S的argument到底说明了一个什么结论呢？“So at any given time if a person knows approximately 50 workers, 1 or more will very likely be unemployed." 1/20大于比1/50，也就是normal rate更大? 但S的目的不是要说normal rate比R假设的rate小吗? 谢谢！