Since the firm is producing in a perfectly competitive market, the firm views the output price as exogenous. It should produce up to the point at which P = SMC(Q), that is, so that 10 = Q. So it should produce 10 units of output. The total cost function increases in Q, and at an increasing rate. Total Profit at first increases in Q and then decreases. From the graph, it appears that Profit is maximized when Q is about 10,