Approximately 7% of the Canadian population have type O- blood and are considered "universal donors". A blood clinic receives donations from 20 people on a particular day.

a. What is the probability that exactly 2 blood donors on that day are universal donors?

b. What is the probability that at most 2 blood donors on that day are universal donors?

c. What is the probability that at least 3 blood donors on that day are universal donors?

d. How many universal donors are expected to be seen on that day?

e. What is the standard deviation of the number of universal donors you would see in a day?