The Heinlein and Krampf Brokerage firm has just been instructed by one of its clients to invest $$250,000$ of her money obtained recently through the sale of land holdings in Ohio. The client has a good deal of trust in the in$$vestment house, but she also has her own ideas about the distribution of the funds being invested. In par$$ticular$,$ she requests that the firm select whatever stocks and bonds they believe are well rated, but within the following guidelines:

$($a$)$ Municipal bonds should constitute at least $20\%$

of the investment.

$($b$)$ At least $40\%$ of the funds should be placed in a

combination of electronic firms, aerospace firms,

and drug manufacturers.

$($c$)$ No more than $50\%$ of the amount invested in

municipal bonds should be placed in a high$-$risk,

high$-$yield nursing home stock.

Subject to these restraints, the client's goal is to max$$imize projected return on investments. The analysts at Heinlein and Krampf, aware of these guidelines prepare a list of high$-$quality stocks and bonds and their corresponding rates of return.