The Solution
Our completed blending model is:
MODEL:
SETS:
NUTS: SUPPLY;
BRANDS: PRICE, PRODUCE;
NCROSSB( NUTS, BRANDS): FORMULA;
ENDSETS
DATA:
NUTS, SUPPLY =
PEANUTS 750
CASHEWS 250;
BRANDS, PRICE =
PAWN 2
KNIGHT 3
BISHOPP 4
KING 5;
FORMULA = 15 10 6 2
1 6 10 14;
ENDDATA
MAX = @SUM( BRANDS( I): PRICE( I) * PRODUCE( I));
@FOR( NUTS( I):
@SUM( BRANDS( J):
FORMULA( I, J) * PRODUCE( J) / 16) <= SUPPLY( I)
);
END
Model: CHESS
An abbreviated solution report for the model follows:
Global optimal solution found.
Objective value: 2692.308
Infeasibilities: 0.000000
Total solver iterations: 2
Variable Value Reduced Cost
PRODUCE( PAWN) 769.2308 0.0000000
PRODUCE( KNIGHT) 0.000000 0.1538461
PRODUCE( BISHOP) 0.000000 0.7692297E-01
PRODUCE( KING) 230.7692 0.0000000
Row Slack or Surplus Dual Price
1 2692.308 1.000000
2 0.000000 1.769231
3 0.000000 5.461538
Solution to CHESS
This solution tells us Chess should produce 769.2 pounds of the Pawn mix and 230.8 pounds of King for total revenue of $2692.30. Additional interesting information can also be found in the report. The dual prices on the rows indicate Chess should be willing to pay up to $1.77 for an extra pound of peanuts and $5.46 for an extra pound of cashews. If, for marketing reasons, Chess decides it must produce at least some of the Knight and Bishop mixes, then the reduced cost figures tell us revenue will decline by 15.4 cents with the first pound of Knight produced and 7.69 cents with the first pound of Bishop produced.