Five percent of U.S. workers use public transportation to get to work. A transit authority offers discount

Question:

Five percent of U.S. workers use public transportation to get to work. A transit authority offers discount rates to companies that have at least 30 employees who use public transportation to get to work. Find the probability that each company will get the discount.
(a) Company A has 250 employees.
(b) Company B has 500 employees.
(c) Company C has 1000 employees.