A certain production process employs two inputs - labor (L) and raw materials (R). Output (Q) is a function of such two inputs and is given by the following relationship:
Q = 6L2 R2 - .10L3 R3.
Suppose that raw materials (input R) are fixed at 10 units.
Determine the number of units of input L that maximizes the total product function.
a. 2
b. 4
c. 3
d. 1