Chapter $3,$ Problem $23$:

A trust officer at the Blacksburg National Bank needs to determine how to invest $$100,000$ in

the following collection of bonds to maximize the annual return.

The officer wants to invest at least $50\%$ of the money in short$-$term issues and no more than

$50\%$ in high$-$risk issues. At least $30\%$ of the funds should go in tax$-$free investments and at

least $40\%$ of the total annual return should be tax free.

a$.$ Formulate an LP model for this problem.

b$.$ Create a spreadsheet model for this problem and solve it using Solver.

c$.$ What is the optimal solution?

a$.$ Write down the LP model.

b$.$ Submit your Excel spreadsheet.

c$.$ In the optimal solution, the amount to invest in bond A is

the amount to

invest in bond $B$ is

the amount to invest in bond $C$ is

the

amount to invest in bond Di

the amount to invest in bond E is

The maximum return is

In your Excel spreadsheet, the decision variables are in cells

objective function is entered in cell