suppose the fimrs hires each unit of labor for $700 per week, and each unit of output sells for $9. How many workers will the firm hire to maximize its profit?

The question is missing the amount of output units that each additional unit of labor generates, but we can calculate how many units each additional unit of labor should produce in order to maximize profit.

In order for a firm to maximize its profit, the marginal revenue product (MRP) = marginal cost (MC).

MRP = output units per additional unit of labor x price per unit = U x $9

MC = $700

U x $9 = $700

U = $700 / $9 = 77.78, so we round up to 78 units

In order to maximize profit, each additional unit of labor must generate 78 additional units of output.