Dan Woodward is the owner and manager of Danís Truck Stop. Dan offers free refills on all coffee orders. He gathered the following information on coffee refills: there is a 30% chance that a customer will not get a refill, a 40% chance that a customer will get one refill, a 20% chance that a customer will get two refills, and a 10% chance that a customer will get three refills. How many refills can Dan expect a customer to get?
I know that 70% of the customers will get a refill, but I do not know how to figure out the # of refills.