Consider 3 consumers of firework display, A, B and C with individual demand functions QA = 40 - 0.5PA, QB = 30 - 0.25PB and QC = 10 - 0.2PC, respectively. If the marginal cost of firework display is a constant amount that is equal to 30, compute the optimal quantity of firework display. If the private market successfully prevents those who do not pay the fee for the firework display and charges $100 for the entrance fee, which customer will pay for the firework display and what is the quantity consumed? Explain.