Can someone please help me with Question 10&11

QUESTION 10 For a given standard deviation, an efficient portfolio will o maximize the expected return. e pinpoint the single best risk-return tradeoff point. minimize the number of securities held in the portfolio. o minimize the portfolio beta, QUESTION 11 Hannah owns the following portfolio of stocks. What is the return on her portfolio? Stock Amount Invested Return on Stock 20,000 9% B -5,000 3% C 15,000 596 5.4596 8.5596 7.2586 6.75