Mixed integer problem I have three trucks delivery ice. Two trucks carry 15 tons, one carries 30 tons. It costs $150 to send the 30 ton truck to location 1; $200 to location 2; and $300 to location 3. I wish to minimize cost and each location must have a truck dispatched to it. X1 = location 1 X2 = location 2 X3 = location 3 Y1 = mixed integer (0,1 or yes no). How would I write the formula and and constraints? I am so burned out on linear programming -- 40 hours per week of studying!

With the information you gave you would send the 30 ton truck to location 1 as 150 < 200 < 300 and ther is no advantage to send it any wgere else. But this is probably too simple. To truly minimize the cost, also need the costs for the 15 ton trucks to each location, and how much ice each location requires. Information on the revenue earned would also be worth while.

This is why the question blew me away - it must be a trick question because it is too easy. Essentially I have to first write the variable definitions and constraints which restrict the amount of ice to any one location. I then have to formulate a Yi (1,0) mixed integer linear program with the cost of sending the 30 ton truck $150 to send the truck to location 1; $200 to location 2; and $300 to location 3. Another poorly written question. I asked the Professor and his response was "re-read the question". Humm