The variance of first $50$ even natural numbers is
🎥 Video solution / Text Solution of this question is given below:
Numbers are $2,4,\dots,100=2\cdot{1,\dots,50}$.
$\operatorname{Var}(1,\dots,50)=\dfrac{50^2-1}{12}=\dfrac{2499}{12}=\dfrac{833}{4}$.
Scaling by $2$: $\operatorname{Var}=4\cdot\dfrac{833}{4}=833$.