\documentclass{ximera}
\title{Ximera Activity}
\author{Jane Doe}
\begin{document}
\begin{abstract}
This is a Ximera document.
\end{abstract}
\maketitle
\section{My first section}
\begin{example}
Did you know that $2\times 3 = 6$?
\begin{explanation}
This is my explanation of my example.
\begin{align*}
2\times 3 &= 2 + 2 + \answer[given]{2}\\
&= 6
\end{align*}
\end{explanation}
\end{example}
\begin{problem}
Here is a multiple choice problem.
\begin{multipleChoice}
\choice[correct]{I'm right!}
\choice{I'm not right}
\end{multipleChoice}
\end{problem}
\begin{exercise}
\begin{selectAll}
\choice[correct]{Select me.}
\choice[correct]{Me too!}
\choice{Not me.}
\end{selectAll}
\end{exercise}
\end{document}