Chapter 5.3, Problem 56E

In Problems 49-64, construct a mathematical model in the form of a linear programming problem. (The answers in the back of the book for these application problems include the model.) Then solve by the geometric method.

Investment. An investor has $\text{\$}24,000$ to invest in bonds of AAA and B qualities. The AAA bonds yield an average of $6\text{\%}$ and the B bonds yield $10\text{\%}$. The investor requires that at least three times as much money should be invested in AAA bonds as in B bonds. How much should be invested in each type of bond to maximize the return? What is the maximum return?