The market for standard toothbrushes is best descibed by perfect competition. The manufactures produce toothbrushes exclusively employing the production factor labor (L) and recruit employees on a competitive labor market. There is a uniform wage of w = 2. Ficed costs are FC = 384. there are eight identical manufactures operating in this market. Their production function is discribed by: q=(L/3).

How large are minimum average total costs (ATC min) and what is total market supply Qs?

a) ATC min = 8; Qs = 1/4 * P

b) ATC min = 96; Qs = 2/3 * P

c) ATC min = 8; Qs = 1/3 * P --> WRONG!

d) ATC min = 96; Qs = 4/3 * P --> WRONG!

e) ATC min = 10; Qs = 1/2 * P

Could you please tell me how to calculate this and what is the right answer?