how to find the amound for Class B for part b-1

The Investments Fund sells Class A shares with a front-end load of 5% and Class B shares with 12b-1 fees of 0.75% annually as well as back-end load fees that start at 5% and fall by 1% for each full year the investor holds the portfolio (until the fifth year). Assume that you have $1,000 to invest and the portfolio rate of return net of operating expenses is 13% annually. If you invest in each fund and sell after 4 years, how much will you receive from each sale? (Round your answers to 2 decimal places. Omit the "$" sign in your response.) Are Class A or Class B shares the better choice for you? Class A Class B If you invest in each fund and sell after 12 years, how much will you receive from each sale? (Round your answers to 2 decimal places. Omit the "$" sign in your response.)