If mean and standard deviation of 5 observations x_1, x_2, x_3, x_4, x_5 are 10 and 3, respectively, then the variance of 6 observations x_1, x_2, …,…

If mean and standard deviation of $\displaystyle 5$ observations $\displaystyle x_1, x_2, x_3, x_4, x_5$ are $\displaystyle 10$ and $\displaystyle 3$, respectively, then the variance of $\displaystyle 6$ observations $\displaystyle x_1, x_2, \ldots, x_5$ and -$\displaystyle 50$ is equal to :