Suppose Melody owns a business giving piano lessons. Assume that the market for piano lessons is perfectly competitive and that the equilibrium price of a piano lesson is $20. Melody’s total costs vary depending on the number of piano lessons she offers each day, as shown in the table below.

Number of lessons per day	Total cost per day ($)
0	30
1	50
2	68
3	78
4	96
5	115
6	138
7	168
8	208

a. When Melody gives 3 lessons per day, what is her average variable cost?

b. What is the profit-maximizing number of lessons for Melody to give each day?

c. What is Melody's daily economic profit at her profit-maximizing number of lessons?