Tính nhanh: \(\Large \dfrac{1}{2} + \dfrac{1}{4} + \dfrac{1}{8} +\dfra

Tính nhanh: 

\(\Large \dfrac{1}{2} + \dfrac{1}{4} + \dfrac{1}{8} +\dfrac{1}{16} + \dfrac{1}{32} + \dfrac{1}{64} + \dfrac{1}{128} + \dfrac{1}{256}\)

• A.

  \(\Large\dfrac{255}{256}\)

• B.

  \(\Large\dfrac{256}{255}\)

• C.

  \(\Large\dfrac{250}{256}\)