The sum of the first $8$ terms of $1 + \dfrac{1}{2} + \dfrac{1}{4} + \dfrac{1}{8} + \cdots$ is —

Question

Accepted Answer

$\dfrac{255}{128}$

Answer

$\dfrac{127}{64}$

Answer

$\dfrac{511}{256}$

Answer

$\dfrac{63}{32}$

The sum of the first 888 terms of 1+12+14+18+⋯1 + \dfrac{1}{2} + \dfrac{1}{4} + \dfrac{1}{8} + \cdots1+21​+41​+81​+⋯ is —