A portfolio is composed of two stocks, A and B$.$ Stock A has a standard deviation of return of $35\%,$ while stock B has a standard deviation of return of $15\%.$ The correlation coefficient between the returns on A and B is $0\mathrm{.}45.$ Stock A comprises $40\%$ of the portfolio, while stock B comprises $60\%$ of the portfolio. What is the variance of the portfolio? What is the Volatility of the portfolio?