gwd-18-15

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.

选哪个？

FACT1: P(A)<(F)     

FACT2: P(F|A)=P(AF)/P(A)  >95%   

SO: P(A|F)=P(AF)/P(F)< P(AF)/P(A)<95%-->E

P(AF)/P(A)  >95%

P(AF)/P(A)>(AF)/P(F)

如何得出P(AF)/P(F)<95%? 为什么不能是P(AF)/P(F)>95%?

我觉得答案应该是B.

因为:A LESS THAN H AND Over 95 percent A HAPPEN WITH  H HAPPEN.

SO, B.