Of all customers purchasing automatic garage door openers, 85% purchase a chain-driven model. Let X = the number among the next 12 purchase who selec the chain-driven model. What is the probability that at most 10 select the chain-driven model?

On a game show, a contestant is given the digits 3, 4, and 5 to arrange in the proper order to form the price of an appliance. If the contestant is correct, he or she wins the appliance. What is the probability of winning when the contestant knows that the price is at least $400?