Society is made up of two individuals, A and B, whose demands for public good X are given in Figure 1. Assuming that the public good can be produced at a constant marginal cost of $6, what is the...

Society is made up of two individuals, A and B, whose demands for public good X are given in Figure 1. Assuming that the public good can be produced at a constant marginal cost of $6, what is the optimal level of output? How much would you charge A and B?