A manufacturing firm estimates that its total production of automobile batteries in thousands of units is (x,

A manufacturing firm estimates that its total production of automobile batteries in thousands of units is ƒ(x, y) = 3x^1/3y^2/3, where x is the number of units of labor and y is the number of units of capital utilized. Labor costs are $80 per unit, and capital costs are $150 per unit. How many units each of labor and capital will maximize production, if the firm can spend $40,000 for these costs?