The XYZ Steel Company produces its own coal for use in its production facility. The
demand for steel is given by Ps = 500 ” 2Qs and the total cost of producing steel is
given by TCs = 175Qs, where Qs is tons of steel per week. The price of coal in a
perfectly competitive market outside the firm is $250 per ton, and the total cost of
producing coal is given by TCc = 40 + 5Qc
2, where Qc is tons of coal per week. How
much should XYZ steel charge itself for coal?
a. $250 per ton.
b. $350 per ton.
c. $500 per ton.
d. $750 per ton.
e. $1,000 per ton.
If Y = (X ” 3)2/ (9 + 12X ” X4), then dY/dX is:
a. [2(9 + 12X ” X4)(X ” 3) + (12 ” 4X3)(X ” 3)2] / (9 + 12X ” X4)2.
b. [2(9 + 12X ” X4)(X ” 3) ” (12 ” 4X3)(X ” 3)2] / (9 + 12X ” X4)2.
c. [2(9 + 12X ” X4)(X ” 3) + (12 ” 4X3)(X ” 3)2](9 + 12X ” X4)2.
d. [2(9 + 12X ” X4)(X ” 3) ” (12 ” 4X3)(X ” 3)2](9 + 12X ” X4)2.
e. [2(9 + 12X ” X4)(X ” 3) ” (12 ” 4X3)(X ” 3)2] / (9 + 12X ” X4).