A year's tuition at a state university cost $250 in 1972 when the CPI equaled 0.418. The cost of a year's tuition at the same state university cost $8,000 in 2016 when the CPI equaled 2.40. The real cost of tuition between 1972 and 2016:

Which statement most adequately describes the productivity of trade relative to the productivity of agriculture and manufacturing?

A) Trade is essential in an economy once agriculture and manufacturing have developed, even though it is not productive. B) Trade is less productive than agriculture or manufacturing. C) The word productive must be applied to agriculture or manufacturing in the same way it is applied to trade. D) Trade is productive only insofar as it distributes newly produced agricultural or manufactured goods. E) Trade is rarely productive because it almost never increases the quantity of goods in the economy.

Which of the following is NOT an example of common property?

A) a trampoline B) air C) gravity D) sunshine