A wireless phone company has a pricing scheme that includes 200 minutes' worth of phone usage in the basic $50. Each minute over and above the first 200 minutes of usage is charged at $0.60 per minute. A) Let x be the number of minutes of phone usage per month. What is the expression for the average cost per minutes if the value of x is between 0 and 200? B) What is the expression for the average cost per minute if the value of x is in the interval (200,300]? C) If phone usage in a certain month is 300 minutes, what is the average cost per minute. Round to the nearest cent.