[问题讨论]GWD-9-Q13

louisehu

问题讨论：

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.


怎么推出E的呢？逻辑错乱ing~~跪谢大牛指点！

susielei

楼主可以在本子上画圈圈来看，因为这里不好画图，所以就用数学符号来代替吧。
感染Asthma的总人数为X1，感染hay fever的总人数为X2。（画一个小圈和一个大圈）
由fact 1得知，X1<X2;由fact 2得知，同时感染了Asthma和hay fever的人数高于95%*X1
再看选项，A和B逻辑错误；
C选项，由于不知道这两种疾病人数占total population的比例，所以C中是得不出比率的
D选项，画圈看更清晰，因为X1与X2的绝对值没给出，X2圈可大可小，所以是比不出具体大小的
E选项，因为X2>X1，所以得两种疾病的人占hay fever总人数的比例肯定低于95%(分子相同，分母更大）

louisehu

多谢楼上！^^

muddycool

我去 我也纠结了好久 结果本质是个数学题···囧

rock19840717

想复杂了