a pension fund manager decides to invest a total of at most 25 million in the US Treasury bonds paying 3% annual interest and in mutual funds paying 5% annual interest. It plans to invest at least 5 million in bonds and at least 10 million in mutual funds. Bonds have an initial fee of 100 per million dollars while the fee for mutual funds is 200 per million. The fund manager is allowed to spend no more than 4,000 on fees. How much should be invested in each to maximize annual interest? what is the maximum annual interest?