19. The demand is negatively sloped, the supply is positively sloped. A $10 per unit tax would a. increase the equilibrium market price by $10 b. increase the equilibrium market price by more than $10 increase the equilibrium market price by less than $10 d. not change the equilibrium market price20. The present value of $200 that will be received 2 years in the future is (i = interest rate per year) a. PV = $200 1+i $200 b. PV = (1+1)2 c. PV = $200/2 1+i $200 d. PV =18. An increase in supply, other things equal, leads to a. an increase in the equilibrium market price and an increase in the equilibrium market quantity b. an increase in the equilibrium market price and a decrease in the equilibrium market quantity c. a decrease in the equilibrium market price and an increase in the equilibrium market quantity d. a decrease in the equilibrium market price and a decrease in the equilibrium market quantity