An industry has only two firms producing outputs y1 and y2, respectively. The first firm has a

cost function of TC(y1) = 20 + 20y1 and the second has a cost function TC(y2) = 10 + 5y2 + y22. The demand function for the product these firms make is Q = 120 - 3P, where Q is the
total output of the two firms. What are the firms' outputs in equilibrium?

1 answer

In equilibrium, the firms will produce outputs such that the market price is equal to the marginal cost of production. The market price is given by the inverse demand function, P = 40 - (1/3)Q. The marginal cost of production for the first firm is MC1 = 20 and for the second firm is MC2 = 5 + 2y2.

Setting MC1 = MC2 = P, we get:
20 = 5 + 2y2
y2 = 7.5

Substituting this value of y2 into the demand function, we get:
Q = 120 - 3(40 - (1/3)Q)
Q = 90

Therefore, the output of the first firm is y1 = 45 and the output of the second firm is y2 = 7.5.