A trust officer at the Blacksburg National Bank needs to determine how to invest $150,000 in the following collection of bonds to maximize the annual return.

Bond	Annual Return	Maturity	Risk	Tax Free
A	9.5%	Long	High	Yes
B	8.0%	Short	Low	Yes
C	9.0%	Long	Low	No
D	9.0%	Long	High	Yes
E	9.0%	Short	High	No

PLEASE SHOW STEP BY STEP spreadsheet models and solver.

The officer wants to invest at least 40% of the money in short-term issues and no more than 20% in high-risk issues. At least 25% of the funds should go in tax-free investments, and at least 45% of the total annual return should be tax free.

1. Formulate the LP model for this problem.
2. Create the spreadsheet model and use Solver to solve the problem.