Suppose there are four firms in a competitive market and that each firm has the following supply function.

Supply functions for competitive firms
Company Supply Function
1 Q1 = 16 + 4P
2 Q2 = -5 + 5P
3 Q3 = 32 + 8P
4 Q4 = - 60 +10P

a. Find the competitive market supply function.
b. If the market demand function for this product is Q = 500 - 2P , what is the competitive market price and quantity.