A firm with a production function Q = KL (where K is units of capital and L is units of labor) has an expansion path that is given by K = 2L. The wage rate (W) is $20 and the rental on capital is $10. Assuming that the firm is using the optimal mix of inputs for any given output level, the total cost when using three units of labor is: $. A. 40 B. 80 C. 120 D. 160

C. 120

Explanation:

The computation is shown below:

                                      (L × K)

Labor L      Capital K   Quantity of Output Q         Total cost TC

1                    2                      2                                       $40

2                   4                      8                                       $80

                                                                   (2 × $20 + 4 × $10)

3                    6                    18                                       $120

                                                                  (3 × $20 + 6 × $10)

4                    8                     32                                      $160

                                                                 (4 × $20 + 8 × $10)

As we can see that if we considered 3 units of labor so the total cost is $120

Hence, the correct option is c.

answer; specific performance;

answer; is usually (less than) the socially optimal level of consumption;