\documentclass[a4paper,10pt]{article}
\usepackage{myXsim}

\author{Benjamin Bertrand}
\title{Échantillonnage}
\date{Novembre 2020}

\DeclareExerciseCollection{banque}
\xsimsetup{
    step=6,
}

\begin{document}

\setcounter{exercise}{16}
\input{exercises.tex}
\vfill
\printcollection{banque}
\vfill
\printcollection{banque}
\vfill

\end{document}