In economics, scarcity implies

Suppose a single-price monopoly sells 3 units of a good at $20 per unit. If the monopoly sells 4 units, the total revenue increases to $72. What price is being charged for 4 units?

A) $52 each B) $18 each C) $60 each D) $12 each E) $20 each

Fiona's hourly wage increases from $8 to $10 . Which of the following describes a consequence of the increase in Fiona's wage?

a. The opportunity cost of Fiona's leisure time has decreased. b. Fiona may choose to work fewer hours due to the increase in her wage. c. If Fiona's labor supply curve is upward sloping, she will choose to work fewer hours. d. Both a and b are correct.