Please explain in detail. Dont use excel. I get stuck a lot, have to solve on paper.

3 You have two financial assets to invest. The first one is a risk-free asset with a return of 8%. The other one is a risky portfolio with an expected return of 16% and standard deviation of 25%. a) If you form a complete portfolio investing 45% of your funds in the risk-free asset and the remaining funds in the risky asset, what is the expected return and standard deviation of your complete portfolio? b) If you want a portfolio with a standard deviation of 20%, what should be the composition of your portfolio? c) If you want a portfolio with an expected return of 10%, what should be the composition of your portfolio?