Avery is in the business of manufacturing phones. She must pay a daily fixed cost to rent the building and equipment, and also pays a cost per phone produced for materials and labor. The labor and materials cost $100 for each phone manufactured, and the total cost of producing 3 phones in a day would be $600. Write an equation for C, C, in terms of p, p, representing total cost, in dollars, of producing pp phones on a given day.