    \begin{exercice*}
      Soit $S$ la suite d\'{e}finie pour $n \in{}\N^*$. On a ${S_n} =
      \sum\limits_{i = 1}^n {{{\left( {\dfrac{1}{3}}
            \right)}^i}}$. Alors :

      \begin{ChoixQCM}{3}
      \item ${S_2} = \dfrac{4}{9}$
      \item ${S_n} = 1 + \dfrac{1}{3} + \dfrac{1}{9} + ... + {\left(
            {\dfrac{1}{3}} \right)^n}$
      \item ${S_n} = \dfrac{1}{2}\left( {1 + {{\left( {\dfrac{1}{3}}
                \right)}^n}} \right)$
      \end{ChoixQCM}
    \end{exercice*}
    \begin{corrige}
      \reponseQCM{a}
    \end{corrige}