- Consider a product market with three consumers X, Y and Z with demand function QX = 6 PX, QY = 3 1/2PY and Q2 = 12 PZ respectively, where P is the price in dollars and QX, QY and 02 are the quantities demanded by Consumer X, Y and Z respectively. - If the product is public good, obtain the marginal social benefit function and draw the diagram. Determine the optimal quantity of the product in the market if the marginal cost of the product is ggfggstant at (a) $4, (b) $9 and (c) $16