The above table shows the marginal benefit from submarines for the only two citizens of a country. Submarines are a public good. If submarines cost $100 a piece to produce, what is the efficient quantity of submarines?

Under Federal Trade Commission merger guidelines, an industry with a Herfindahl-Hirschman index (HHI) of 800 points is considered

A) competitive. B) moderately concentrated. C) concentrated. D) a monopoly.

Moving downward on a downward sloping linear demand curve, the absolute value of the price elasticity of demand

A) is constant. B) increases continuously. C) decreases continuously. D) may either increase or decrease.