ASAP pls

Exercise 1 You hold a stock A that provides you with the following returns Probability Return 10% 22 15 50% 24 20% 30 20% 1/ What is the expected return and the risk of this stock (variance and standard variation)? Suppose you hold a portfolio composed by: 75% of stock A 25% of stock B knowing that the variance of stock Bis 10 and the expected return is 20. The correlation between A and B is 0.4 2/ Calculate the risk and return of this portfolio 3/ What are the new values of the risk and return of this portfolio if the proportion of stock A is now 65%