QUIZ

Question 1/21
Si $S=1024+256+64+\ldots+\dfrac{1}{16}$

Alors $S=?$
  $1024\times\dfrac{1-\left(\dfrac{1}{4}\right)^{8}}{\dfrac{3}{4}}$
  $1024\times\dfrac{1-4^{7}}{1-4}$
  $\dfrac{1}{16}\times4^{6}$
  $\dfrac{1}{16}\times\dfrac{1-4^{7}}{-3}$
  $\dfrac{1}{16}\times\dfrac{1+4^{8}}{1+4}$