An investor has 4 different financial instruments (1, 2, 3, 4) to invest. His objective is to maximize his profit for next year. He has 120000$ to invest. The annual returns for the instruments are 2%, 5%, 6% and 8%, respectively. The investor wants to obey following restrictions due to his concerns about the risk of his investment: - He does not want to invest more than 30% of his money on 3 and 4 combined. - The amount invested on 2 and 4 should be less than half the amount invested in 1 and 3. - At least 25% of the initial cash should be invested in 1 and 2. Formulate a linear programming model for this