The percentage of people in a population with a certain ailment (Ailment A) is 15%.

A. If you select a sample of 10 people from this population, what is the probability at least half of them have Ailment A?

B. What is the probability at most 3 of them would have this ailment?

C. If you select a sample of 100 people, what is the probability that less than 10 will have ailment A? Use the Normal approximation technique.

D. What is the probability, in your sample of 100, that at least 20 will have Ailment A?