In this part, we model the situation as follows:
\begin{itemize}
  \item the condition of a scooter is independent of that of the others;
  \item the probability that a scooter is in good condition is equal to 0.8.
\end{itemize}

We denote $X$ the random variable which, to a batch of 15 scooters, associates the number of scooters in good condition.\\
Since the number of scooters in the fleet is very large, the sampling of 15 scooters can be assimilated to a draw with replacement.

\begin{enumerate}
  \item Justify that $X$ follows a binomial distribution and specify the parameters of this distribution.
  \item Calculate the probability that all 15 scooters are in good condition.
  \item Calculate the probability that at least 10 scooters are in good condition in a batch of 15.
  \item We admit that $E(X) = 12$. Interpret the result.
\end{enumerate}