Question

It is estimated that only about 4% of people have Type AB blood.

A) On average, how many donors must be checked to first find someone with Type AB blood?

B) What is the probability that the 20th donor is the first one to have Type AB blood?

C) What is the probability that at most five people will have to be checked before first finding someone with Type AB blood?

D) What is the probability that we won’t find a Type AB donor before the tenth person?

Answer 1

Explanation:

The probability of finding a person with Type AB blood is 4%, or 0.04. Therefore, on average, you would need to check 1/0.04 = 25 people to find someone with Type AB blood. b) The probability that there is a Type AB donor among the first 3 people checked can be calculated using the binomial probability formula.