Let me just write it using this sigma notation. So another way of writing the variance of X plus Y is to write the standard deviation of X plus Y squared. And that's going to be equal to the variance of X plus the variance of Y. Now what is the variance of X? Well, it's the standard deviation of X squared, 0.8 squared. This is 0.64, 0.64. The standard deviation of Y is 0.6.