Question b and c I am struggling on

2. As the owner of a hardware store, you are concerned about the supply of white paint through the weekend. You have 13 gallons of paint left in stock. Assume that there is a 20% chance that any customer buying paint will purchase a gallon of white paint. With 25 customers purchasing paint over the weekend: a) How many gallons of white paint will you expect to sell? b) What is the variance in the number of gallons of white paint sold? c) What is the probability that you will not have enough gallons of white paint to meet demand? k