A market contains two stocks. The following information is known:

The returns of the stocks are independent

Stock 1 has an average return of 5% and a risk of 10%

Stock 2 has an average return of 10% and risk of 20%

a) Find the weights of all portfolios with risk 20% and the returns of these portfolios.

b) Find the weights of the portfolio with the minimal possible risk

c) Calculate the return and risk of the portfolio in part b)