GWD-9-Q13

Gracespa

向大家请教
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.

jasonlove

因为A<HF，所以95%A<95%HF

shijianfeile

可以画了个来韦恩图来看选项，看得很清楚，当然其实不需要那么麻烦，呵呵

uniquenellier

A并B>95%
那么非A交非B肯定要<5%的啦
不然还得了？