If 80% of all business airline travelers prefer to carry on baggage rather than check it, calculate

Question:

If 80% of all business airline travelers prefer to carry on baggage rather than check it, calculate the probabilities of the following events from a random sample of 25 business travelers:
a. Exactly 15 prefer to carry on baggage
b. Fewer than 5 prefer to check baggage
c. More than 10 prefer to carry on baggage