(Consumer Surplus) suppose the linear demand for shirts slopes downward and that consumers buy 500 shirts per year when the price of shirts is $30 and 1,000 shirts per year when the price is $25.

a. compared to the prices of $30 and $25, what can you say about the marginal valuation that consumers place on on the 300th shirt, the 700th shirt, and the 1200th shirt they might buy each year?

b. With diminishing marginal utility, are consumers deriving any consumer surplus if the price is $25 per shirt? Explain.

c. Use a market demand curve to illustrate the change in consumer surplus if the price drops from $30 to $25.