Solve the Problem $P ( x ) = - 30 x ^ { 2 } + 1,560 x - 1,470$

Multiple Choice

Solve the problem.
-The daily profit in dollars made by an automobile manufacturer is $P ( x ) = - 30 x ^ { 2 } + 1,560 x - 1,470$ where x is the number of cars produced per shift. Find the maximum possible daily profit.

A) $17,305
B) $20,315
C) $18,810
D) $15,989