If the selling price of a firm's product is $200 and the estimated average cost of producing this product is $150, what is the firm's markup?

A simultaneous decrease in both the demand for MP3 players and the supply of MP3 players would imply that

a. both the value of MP3 players to consumers and the cost of producing MP3 players has increased. b. both the value of MP3 players to consumers and the cost of producing MP3 players has decreased. c. the value of MP3 players to consumers has decreased, and the cost of producing MP3 players has increased. d. the value of MP3 players to consumers has increased, and the cost of producing MP3 players has decreased.

Refer to the graph shown, which shows the demand and supply for a new vaccine against the common cold. Once vaccinated, a person cannot catch a cold or give a cold to someone else. The socially efficient level of output is:

A. greater than or less than Q0 depending on the income elasticity of demand and the effectiveness of the vaccine. B. less than Q0. C. equal to Q0. D. greater than Q0.