Let's let
<u>x = the number of chef salads, x>=0</u>
<u>y = the number of Caesar salads, y>=0</u>
The constrains are:
40 <= x <= 60
35 <= y <= 50
x + y <= 100
The objective function here is F(x, y) = 0.75x + 1.20y
The corner points are (40, 35), (60, 35), (60, 40), (50, 50) and (40, 50).
F (40, 35) = 0.75*40 + 1.20*35 = $72
F (60, 35) = 0.70*60 + 1.20*35 = $84
F (60, 40) = 0.75*60 + 1.20*40 = $93
F (50, 50) = 0.75*50 + 1.20*50 = $97.50
F (40, 50) = 0.75*40 + 1.20*50 = $90
Thus, we conclude to maximize the profit 50 Chef and 50 Caesar salads should be prepared.