A person can develop or outgrow asthma at any age. In children under ten, asthma is twice as likely to develop in boy...

shafieiava October 2, 2019

Why is D wrong?

I chose D because I thought it would rule out an alternate cause and therefore strengthen the answer. Can you please explain how you would eliminate this answer choice?

Create a free account to read and take part in forum discussions.

Already have an account? log in

SamA October 2, 2019

Hello @shafieiava,

This is a question that seems very complicated at first, but ends up being pretty simple. It comes down to the difference between percentages vs. quantities.

Premise: Boys under 10 are twice as likely to develop asthma as girls under 10. (We are talking about likelihood here, so this is a percentage. For example, it could be 30% of boys get asthma and 15% of girls get asthma.)

Premise: Boys are less likely than girls to outgrow asthma.

Premise: By adolescence, the percentage of boys with asthma is the same as the percentage of girls with asthma. (For example, 25% of adolescent boys have asthma and 25% of adolescent girls have asthma.)

To answer this question, we only need this third premise. It asks us to convert this percentage into an actual number of adolescents.

Conclusion: The number of adolescent boys with asthma is the same as the number of adolescent girls with asthma.

What more do we need in order to make this conclusion? We need to know the total number of adolescent boys and girls in the population. If 25% of each group have asthma, and there are 100 boys and 100 girls, then we know there are 25 boys with asthma and 25 girls with asthma. This is why C is correct.

D is incorrect because the cause of asthma is not relevant to this question. This is why eliminating an alternative cause doesn't help us.