59. Courtesy Calls makes telephone calls for businesses and charities. A profit of $0.50 is made for each business call and $0.40 for each charity call. It takes 4 min (on average) to make a business call and 6 min (on average) to make a charity call. If there are 240 min of calling time to be distributed each day, how should that time be spent so that Courtesy Calls makes a maximum profit? What changes, if any, occur in the maximum profit and optimal production policy if they must make at least 12 business and 10 charity calls every day?