X=\sum_{k=1}^n\chi_{\{X_k=6\}}, \chi_{\{X_k=6\}}\sim \left(\begin{array}{cc} 
0 & 1 \\
\frac{5}{6} & \frac{1}{6} \\
\end{array}\right) \Rightarrow X\sim B(n,\frac{1}{6})