【求助】GWD-9-Q13 找不出逻辑关系

Maybejessica

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                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.

为什么选E啊？

soubixl

题目中说了A没有HF常见，说明HF总人数比A人数多。同时患有两种病的人数是确定的，也就是说百分比中的分子都是一样的，分母是总人数，HF要大于A，因此百分比要小于A

Maybejessica

E选项是指在患HF的人中，同时患A的人地百分比小于95%吗？

soubixl

不管是HF中患A的还是A中患HF的，人数都是一样的，都是指同时患HF和A的人数。类似韦恩图的交集，over 95 percent of people who have asthma also suffer from hay fever.指的是用同时患A和HF的人数比上A的总人数。E选项中The percentage of people suffering from hay fever who also have asthma is lower than 95 percent.指的是同时患A和HF的人数比上HF的总人数。分子都是同时患A和HF的人数，分母患HF的总人数大于患A的总人数。分子相同时，分母越大的，数值越小，所以小于百分之九十五

Maybejessica

谢谢，明白了。