再问一题

evelyn205205

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.
ANSWER: E

sdcar2010

This is a must-be-true question: inference.

Only E is true becasuse A is less common than HF.  Therefore the total number of people who have HF is bigger than that of who have A.  Then it is a simple math problem to calculate the percentages for comparison.

evelyn205205

BUT WHY C IS NOT A CORRECT ANSWER?
THERE ARE MORE THAN 95% OF PEOPLE WHO HAVE BOTH OF THE DISEASES.

sdcar2010

Two hundred people have hay fever.  One hundred people have asthma. Out of the 100 people who have asthma, 95 of them have hay fever, in other words, 95% of the people who have asthma also have hay fever.

Then out of the 200 people who have hay fever, again 95 of them have asthma.  Translation: only 47.5% of the people who have hay fever also have asthma.

Simple math.

sdcar2010

Again, remember this is a must be true question.  Apparently choice C is not ALWAYS right since the total population cannot be that sick.

LS, you need to understand the definition of denominator.

evelyn205205

THX FOR YOUR HELP
I MISUNDERSOOD THE SECOND FACT.

jyw0411lsq

感觉E 不好翻译啊，能解释下E么？
我的理解是，不知道对不对？
在得hay fever 里面的人中又得 asthma得人 占      所有的hay fever的人数    的比例是小于95%
  题目中的小于95 %后面是不是省略了什么东西，到底谁跟谁比例啊？

sdcar2010

E.The percentage of people suffering from hay fever who also have asthma is lower than 95 percent

在得hay fever 里面的人中, 得 asthma 的人小于95%.

Less than 95% of the people who suffer from hay fever also suffer from asthma.