逻辑题求解-1

yubem

Fact:  Asthma, a bronchial condition, is much lesscommon ailment than hay fever, an allergic inflammation of the nasal passages.
Fact:  Over 95 percent of people who have asthma alsosuffer from hay fever.

If the informationgiven as facts above is true, which of the following must also be true?
A.   Hayfever is a prerequisite for the development of asthma.
B.   Asthmais a prerequisite for the development of hay fever.
C.   Thosewho have neither hay fever nor asthma comprise less than 5 percent of the totalpopulation.
D.   Thenumber of people who have both of these ailments is greater than the number ofpeople who have only one of them.
E.    Thepercentage of people suffering from hay fever who also have asthma is lowerthan 95 percent
为什么选择E呢？

edwinwos

very good explanation!

lnl555

Fact 1： A 小于 H
Fact 2:        A           非A
           H  95%A    H-95%A
        非H  5% A  
A,B 均无法确定，排除
C 无法确定，不知道总人数
D， 5%A+H-95%A=H-90%A   跟95%A的大小无法比较
E， the percentage= 95%A/H   因为A小于H，所以小于95%