If Green Acres Turf Farm's total cost of producing acres of sod is TC = 4Q2 + 25Q + 30, the marginal cost of producing the 20th acre of sod is
A)$30.
B)$25.
C)$105.
D)$185.
E)$345.

Question

Quizplus · Accepted Answer

The marginal cost (MC) is the derivative of the total cost (TC) function with respect to quantity (Q). The derivative of TC = 4Q^2 + 25Q + 30 is MC = 8Q + 25. Plugging Q = 20 into the MC equation gives MC = 8(20) + 25 = 185.

If Green Acres Turf Farm's Total Cost of Producing Acres