The table below provides information for the demand and supply of large pizzas:
Quantity of large pizzas demanded: 0, 20, 40, 60, 80, 100
Quantity of large pizzas supplied: 60, 50, 40, 30, 20, 10
Price: $24, $20, $16, $12, $8, $4
Referring to the diagram above, answer the following questions:
a. If the price of large pizzas is currently $20, there is a surplus of 30 large pizzas.
b. If the price of large pizzas is currently $8, there is a shortage of 60 large pizzas.
c. At the market equilibrium price, large pizzas are exchanged. (Give your answer to the nearest whole number.)