The cost and output schedule of a firm is shown in the table below.

Output (kg)	0	15	35	60	85
Variable cost ($)	0	30	55	75	90
Total cost ($)	15	45	70	90	105
Total revenue ($)	0	30	70	120	170

(a) Using the data in the table, at each level of output, calculate the firm's
(i) marginal revenue
(ii) marginal cost.

(b) At what output level did the firm:
(i) break even
(ii) make the highest profit
(iii) attain equilibrium

(c) Identify the market structure in which the firm operates