Stock X has a return of $15$ percent and a standard deviation of return of $10$ percent. Stock Y has a return of $30$ percent and a standard deviation of return of $20$ percent. The covariance of the two stocks is $100.$ If you invest $60$ percent of your funds in stock X and $40$ percent in stock Y$,$ what is the expected return of your portfolio? what is the standard deviation of your portfolio?