By graphing, find the minimum value of C = 12x + 75y subject to these constraints.

4x + 5y ≥ 40
4x + 20y ≥ 100
24x + 20y ≥ 240
x ≥ 0, y ≥ 0

(a) The minimum value of C is   and this occurs when x =   and y =   .

(b) There is another corner point which does not lie on the x or y axis. Its coordinates are x =   and y =