3. Tanah Designers sells each of its women's suits to retail stores based upon volume discount as follows: a $125 for shipping and handling charge, $325 per suit for the first 50 suits, $275 per suit for the next 50 suits and $195 per suit for each suit in excess of 100. a) Determine the cost function. b) What is the average cost of 80 suits? c) How many suits were purchased if the total cost was $49,625