Price (dollars per pound)	Quantity supplied (thousands of pounds per year)	Quantity demanded (thousands of pounds per year)
21	120	60
18	100	100
16	80	140
12	60	180
9	40	220

1. The United States imports cheese from a variety of countries. The table gives the domestic supply of, and demand for, cheese in the United States. The world price of cheese is $12 per pound, and trade is unrestricted.

a. How many pounds of cheese are consumed in the U.S? b. How many pounds of cheese are produced in the U.S? c. How many pounds of cheese are imported into the U.S?