Hello, I would like some help to solve this question. Thank you.

2. Suppose that the demand functions for a good for two groups of consumers (A and B) are given by QA = 12 - 2P and QB = 8 - P, respectively, where Q is the per unit quantity demanded. The marginal cost to provide the good is constant at $6.50 per unit. There are no externalities in the market. (a) Derive the aggregate demand function and find the socially efficient quantity if the good is a public good. Present the equilibrium graphically. (b) Derive the aggregate demand and find the socially efficient quantity if the good is a private good