In a market with invented figures, marginal private cost is MPC = 10 + Q, marginal social cost is MSC = 10 + 3Q and marginal benefit (demand) is MB = 40 − Q, where Q is output in units and costs and benefits are in $ per unit. Calculate the market output, the socially optimal output and the welfare loss at the market output.

HL Paper 3-style calculation (standalone practice; not an IB question).