Problem: Eastern Alabama Trust invests in various types of securities. A financial advisor there is about to build an investment portfolio for a client who has $100,000 to invest. The four investments available are A, B, C, and D. Investment A will earn 4 percent and has a risk of two "points" per $1,000 invested. B earns 6 percent with 3 risk points; C earns 9 percent with 7 risk points; and D earns 11 percent with a risk of 8. The client has put the following conditions on the investments: A is to be no more than one-half of the total invested. A cannot be less than 20 percent of the total investment. D cannot be less than C. Total risk points must be at or below 1,000. Please explain your answer and also provide examples

Required:

Question 1: What are the Decision Variables?

Question 2: What is the Objective Function?

Question 3: What are Constraint Equations including non-negativity constraints?