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标题: 请教GWD-9-Q13 [打印本页]

作者: sarahzhensh 时间: 2008-7-20 09:58
标题: 请教GWD-9-Q13

Fact: Asthma, a bronchial condition, is much less common ailment than hay fever, an allergic inflammation of the nasal passages.

Fact: over 95 percent of people who have asthma also suffer from hay fever.

If the information given as facts above is true, which of the following must also be true?

A. Hay fever is a prerequisite for the development of asthma

B. Asthma is a prerequisite for the development of hay fever

C. Those who have neither hay fever nor asthma comprise less than 5 percent of the total population

D. The number of people who have both of these ailments is greater than the number of people who have only one of them

E. The percentage of people suffering from hay fever who also have asthma is lower than 95 percent.

答案是E，我是用排除法做的。

但大家能给我解释一下E具体为什么对吗？

谢谢大家了

作者: sarahzhensh 时间: 2008-7-21 08:24

拜托大家给个解释吧！

作者: sarahzhensh 时间: 2008-7-26 09:20

ding

作者: maggiecookies 时间: 2008-7-26 11:14

这是一道数学题, 是个集合问题.

hay fever who also have asthma =who have asthma also suffer from hay fever. (虽然这个交集占H, 或A 的比例不一样, 但占总人口是一样的呀)

A X 95% = HAY FEVER

现在, A占人口的百分比是不知道的, A 在 0---100% 之间, 所以推出E .

作者: sarahzhensh 时间: 2008-7-26 11:38

谢谢你，但我有个疑惑。按照你的方法，只要知道第二个条件即（over 95 percent of people who have asthma also suffer from hay fever.

）就可以推出了是吗？

并且题干中给的是 over 95 即大于95%，按照 “A * 一个大于95%的数=H”，是可以找到一个，H是不一定小于95%的。是不是因为有第一个条件A非常less common,所以A很小，那么乘积H就小于95%呢？但我总感觉这样不严格阿！

作者: sarahzhensh 时间: 2008-7-28 08:12
ding

作者: fiona_hq 时间: 2009-7-21 20:53
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