How to calculate $\sum\limits_{n = 1}^\infty{(0.8)^n}$?

How to calculate $\sum\limits_{n = 1}^\infty{(0.8)^n}$?

pHow to calculate $\sum\limits_{n = 1}^\infty{(0.8)^n}$?/p pI notice that
$0.8^n$ is a geometric series with $a = 0.8$ and $r = 0.8$. So
$\frac{0.8}{0.2} = 4$ but the answer is $0$?/p