Mr. Martin has invested one-third of his fund in stock A and two-thirds of his fund in stock B.Expected returns of stock A and B are 15% and 21% respectively and standard deviation of returns of stock A and B are 18% and 25% respectively. correlation between the returns of A and B is 0.50. What are the expected return and standard deviation of return of Mr. Martin's portfolio? (You must show all necessary workings)