Sometimes a GMAT Critical Reasoning problem won’t seem like an argument at all! In fact, it’ll be more like a data sufficiency question, a presentation of facts we then have to make some sense of. Let’s take a look at one of these Verbal oddities:
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
FACTS: Hay Fever is more common than Asthma; 95% of asthma sufferers have hay fever.
Let’s say 100 people suffer from Asthma. 95 of them also have hay fever. Since hay fever is more common, there must be more than 5% of people who suffer from hay fever only.
For (E), if this was true out of 100 people who have hay fever, 95% of those have asthma as well; 95 people have both, and only 5% would only have asthma. This contradicts our interpretation of the facts. We need MORE than 5% to suffer from hay fever only. (E) is the correct choice!