Can anyone help me with this?

You have $100,000 to invest in either Stock D, Stock F, or a risk-free asset. You must invest all of your money. Your goal is to create a portfolio that has an expected return of 12 percent. Assume D has an expected return of 15.5 percent, F has an expected return of 11.4 percent, and the risk-free rate is 6.25 percent. Required: If you invest $50,000 in Stock D, how much will you invest in Stock F?