For a company that produces respiratory masks, the Cobb-Douglas function is given by where "x" represents the units of labor ($100 per unit) and "y" represents the units of capital ($150 per unit). The total costs of labor and of capital are limited by an amount of $70,000.

a. When does the maximum level of production occurs?

b. What is the maximum level of production of repiratory masks?

c. Find , the marginal productivity of the capital and interpret the answers.

f(x,y) = 120x1/3y2/3