According to the American Cross, about one out of nine people in the U.S. have type B blood. Suppose the blood types of people arriving at a blood drive are independent. In this case, the number of Type B blood types that arrive roughly follows the Poisson distribution.
What is the probability that over 14 people out of these 100 have Type B blood?
What is the probability that more than 23 people arrive before a person with type B blood is found?
