\section*{Part A}
A competitor participates in an archery competition on a circular target. With each shot, the probability that he hits the target is equal to 0.8.

\begin{enumerate}
  \item The competitor shoots four arrows. It is considered that the shots are independent. Determine the probability that he hits the target at least three times.
  \item How many arrows should the competitor plan to shoot in order to hit the target an average of twelve times?
\end{enumerate}