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Let X = the number of the magazine covers,
Y = the number of logos.
Then the profit function is
P(X,Y) = 800*X + 500*Y (1) dollars.
The restrictions are
4*X + 2*Y <= 24 (2) (hours per week)
2*X + 0.5*Y <= 10 (3) (hours per week)
Y <= 4X (4) ("no more than 4 logos for each magazine cover")
Other restrictions are non-negativity
X >= 0; Y >= 0.
The feasible domain is shown in the plot below.
Plot 4*X + 2*Y = 24 (red); 2*X + 0.5*Y = 10 (green); and Y = 4X (blue)
It is the quadrilateral in QI, adjacent to x-axis and bounded by the blue, red and green lines.
It has vertices
P1 = (2,8)
P2 = (4,4) and
P3 = (5,0) (the green line x-intercept).
According to the Linear Programming method, we should calculate and compare the values of the profit function at these three points
at P1: P(2,8) = 800*2 + 500*8 = 5560 dollars;
at P2: P(4,4) = 800*4 + 500*4 = 5200 dollars.
at P3: P(5,0) = 800*5 + 500*0 = 4000 dollars.
The maximum value of the profit function is at P1.
It is the optimal solution.
Answer. Optimal solution to the problem is 4 magazine covers and 8 logos.
It satisfies the restrictions and gives maximal profit of 5560 dollars.
Solved.
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To see other similar problems solved by the Linear Programming method, look into the lesson
- Solving minimax problems by the Linear Programming method
in this site.