The manager of a local monopoly estimates that the elasticity of demand for its product is constant and equal to -3. The firm's marginal cost is constant at $10 per unit.

a. Express the firm's marginal revenue as a function of its price.

Instruction:Enter your response rounded to two decimal places.

MR=P

b. Determine the profit-maximizing price.

Instruction:Use the rounded value calculated above and round your response to two decimal places.

$