Question

A firm is using 30 units of capital and 30 units of labor to produce 90 units of output. Capital costs $500 per unit and labor $5,000 per unit. The last unit of capital added 5 units of output, while the last unit of labor added 45 units of output. The firm is /using the cost-minimizing combination of capital and labor. /should use more of both inputs in equal proportions. /should use less of both inputs in equal proportions. /could produce the same level of output at a lower cost by using more capital and less labor. /could produce the same output at a lower cost by using less capital and more labor.