There are three types of firm in the plastic industry (the sellers are price taker). The total cost functions for the three types of firm are shown as follow: 1 = 1600 + 1001 + 1 2 2 = 3200 + 22 2 3 = 2003 There are 80 Type 1 firms, 120 Type 2 firms and 150 Type 3 firms in the market. Graphically construct the long run market supply curve.