A Firm's Average Cost Function Is Given By $A C = \frac { 800 } { Q } + 2 Q + 18$

Multiple Choice

A firm's average cost function is given by $A C = \frac { 800 } { Q } + 2 Q + 18$ Find, to the nearest whole number, the value of Q at the lowest point on the graph of AC plotted against Q, in the interval, 0 c Q c 30.

A) 25
B) 20
C) 15
D) 5
E) 10