Assume a monopoly has the following demand schedule:

Price         Quantity
$20 ................200
15 ..................300
10 ..................500
5.....................700

a. Calculate total revenue at each P and Q combination.
b. Calculate marginal revenue per unit for each decrease in price.
c. For the change in price from $20 to $15, is demand elastic or inelastic? How much revenue does the firm lose from reducing the price on the 200 units it could have sold for $20? How much revenue does the firm gain from selling 100 more units at $15? Compare the two changes; then compare these changes with MR.
d. Answer part c for the price change from $15 to $10.