Final answer:
In perfect competition, a firm maximizes profits by determining the level of output where marginal revenue (MR) equals marginal cost (MC). For this firm, given a price of $18, the profit-maximizing level of output (Q) can be found by setting MR = MC and solving for Q.
Step-by-step explanation:
In perfect competition, a firm maximizes profits by determining the level of output where marginal revenue (MR) equals marginal cost (MC).
The profit-maximizing level of output (Q) can be found by setting MR = MC and solving for Q.
For this firm, given a price of $18, the profit-maximizing level of output (Q) would be the quantity where MR = MC.