formulate but do not solve the linear programming problem. Tracy has at most $200,000 to invest in stocks,bonds, and money-market funds. She expects anual yields of 15%, 10%, and 8%, respectively, on these investments. If Tracy wants at least $50,000 to be invested in money-market funds and requires that the amount invested in bonds be greater than or equal to the sum of her investments in stocks and money-market funds, determine how much she should invest in each vehicle in order to maximize the returns on her investments.