GWD-18-Q15

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

请问大家：
1    Fact2: over 95% of people who have A also suffer from F. 用概率表示，是：p(AF)>95%  还是 P(F\A)>95%

2     E选项中：A. The percentage of people suffering from hay fever who also have asthma is lower than 95 percent
表示：P（AF）<95% 还是P(A/F)<95%  ??

我倾向于1 .P(F\A)>95%       2.  P(A/F)<95% 

你这个表示看不太明白

fact2 是说得asthma的人里有95%都得了fever(也就是得asthma的人一般都伴随了fever)

E 感染f的人里不到95%的得了A

注意much less common 就不会错了

用个最简单的方法 X个人哮喘 Y个人花粉热 96%X个既有哮喘又有花粉热 96%X/Y 一定比95%小 （因为X比Y小很多）