The sum of the first $n$ terms of the series $7 + 77 + 777 + \ldots$ is —

Question

Accepted Answer

$\dfrac{7}{81}\left(10^{n+1} - 9n - 10\right)$

Answer

$\dfrac{7}{9}\left(10^{n} - 1\right)$

Answer

$7n$

Answer

$\dfrac{7}{9}\left(10^{n+1} - 9n\right)$

The sum of the first nnn terms of the series 7+77+777+…7 + 77 + 777 + \ldots7+77+777+… is —