Problem I: An investor wants to maximize his revenues from an investment in three stocks: A, B, & C, with a yield of: 5%, 8%, & 6% respectively. Stock A will get at most 40%, while stock B has a weight at least 30% of A and C together. A market study shows that the demand of stock C will exceed $2000. The investor has a budget of $10000. Formulate this as a linear programming problem.