Share
Explore BrainMass

Constraints

I supplied my objective function and constraints and I am obviously off. I don't understand why it is selling in month one rather than month three. Please point out the correct objective function and constraints.

6. You own a wheat warehouse with a capacity of 20,000 bushels. At the beginning of month 1 you have 6000 bushels of wheat. Each month, wheat can be bought and sold at the price per bushel shown in the table below:

Month Selling Price $ Purchase Price $
1 3 8
2 6 8
3 7 2
4 1 3
5 4 4
6 5 3
7 5 3
8 1 2
9 3 5
10 2 5

At the beginning of each month you observe the amount of wheat you have on hand. You first sell some quantity ranging from zero to the entire amount that you have. You then buy as much wheat as you wish subject to the constraint that the amount you buy plus the unsold portion of the month's beginning inventory cannot exceed the warehouse capacity. Formulate and solve an LP to find the amounts bought and sold each month so that the net revenue at the end of 10 months is maximized.

Attachments

Solution Preview

Your Objective function is:
MAX 3S1 + 6S2 + 7S3 + S4 + 4S5 + 5S6 + 5S7 + S8 + 3S9 + 2S10
-8P1 - 8P2 - 2P3 - 3S4 - 4S5 - 3S6 - 3 S7 - 2S8 - 5S9 - 5S10

The total Selling price is the sum of the number of bushels sold in each month times the selling Price in that month
The ...

Solution Summary

The constraints for objective functions are determined,

$2.19