Suppose that a shipment of 250 netbooks contained three defects, and 247 good units. Find the

probability that when a company buys three units from this sample, they will receive:

a) There are three good units.

b) All three units will be defective.

c) There will be at least one unit that is good.

At a ceremony at a naval flight school, there were 18 Marines, 10 members of the Navy and three

members of the Coast Guard who were given their wings. If we were to select three pilots at random to

feature in an advertisement, find the probability that there will be:

a) One member from each of the four branches of the service.

b) Exactly three Marines out of the three chosen.