Total physical product shows what happens to the quantity of an output when the firm changes the quantity of an input

Borrowing to fund investment projects until the marginal rate of return falls to ________ is optimizing investment strategy for ________

A) the borrowing rate, businesses and governments B) the borrowing rate, businesses but not governments C) the borrowing rate, governments but not businesses D) zero, businesses and governments E) zero, governments but not businesses

Which of the following statements is supported by the research of economic historians?

(a) Canals and railroads were built with a mixture of private and public enterprise and financing. (b) Canals and railroads were built largely without U.S. government participation. (c) Canals were built with public assistance, but railroads were built with almost no government assistance. (d) Railroads were built with public assistance, but canals were built by private enterprise.