Joseph is going on a trip and he needs to rent a car. He looks online and finds two companies that offer different pricing options for car rentals. Company A charges $0.25 per mile plus a $50 rental fee. Company B charges $0.45 per mile plus a $20 rental fee. What is the maximum number of miles that Joseph can drive in order for Company B to be a better buy? The company charges only for whole number mileage (not fractional increments of miles driven).