Gilberto's profit is maximized when he produces 3 shirts. When he does this, the marginal cost of the previous shirt he produces is $10 , which isless than the price Gilberto receives for each shirt he sells. The marginal cost of producing an additional shirt (that is, one more shirt than would maximize his profit) is $ , which isgreater than the price Gilberto receives for each shirt he sells. Therefore, Gilberto's profit-maximizing quantity corresponds to the intersection of themarginal cost and marginal revenue curves. Because Gilberto is a price taker, this last condition can also be written as P=MC .