Exercise sheet with two enumerated columns

Question

Do you have a simple, minimal template to type Exercise sheets with exercises enumerated with two columns (please check image).

Thank you.

Answer 1

Unless there should be no balanced heights of the \item in the multicol environment this is quite easy. The enumitem package isn't necessary at all, but might help for some more 'sophisticated' numbering/labeling of the items.

\documentclass{article}
\usepackage{blindtext}    
%\usepackage{enumitem}

\usepackage{multicol}

\begin{document}

\begin{enumerate}
\item Calculate that 
\begin{multicols}{2}
  \begin{enumerate}
    \item A
    \item B
    \item C
    \item D
    \item E
    \item F
    \item G
    \item H
    \item I
    \end{enumerate}
\end{multicols}
\item Another question -- \blindtext
\item Yet another question -- \blindtext
\end{enumerate}
\end{document}

Answer 2

You also can have a horizontal enumeration, which more natural, in my opinion, either with the tasks package, or with shortlst. You can choose the number of columns with the nc key (default is $3$) and the interlining with the il key, defaulting to $1$. Here is a demo of both ways:

\documentclass{article}

\usepackage[utf8]{inputenc}
\usepackage{tasks}
\settasks{counter-format=(tsk[a]),label-width=1.5em}
\usepackage{shortlst,setspace,xkeyval}%
\makeatletter
\newcounter{ncol}
\define@key{lex}{nc}[3]{\setcounter{ncol}{#1}}%% 3 columns by default
\define@key{lex}{il}[1.5]{\def\@intln{#1}}% interlining![1]
\newenvironment{tabenumerate}[1][]{%
\setkeys{lex}{nc,il,#1}
\settowidth{\labelwidth}{\mbox{(m)}}
\setlength{\leftmargini}{\dimexpr\labelwidth+\labelsep\relax}%[1][3]
\setlength{\shortitemwidth}{\dimexpr\linewidth/\value{ncol}-\labelwidth-2\labelsep\relax}%
\renewcommand{\labelenumi}{(\alph{enumi})}
\setstretch{\@intln}
\begin{shortenumerate}}%
{\end{shortenumerate}
 }%
 \newcommand\paritem[2][1]{\item \parbox[t]{#1\shortitemwidth}{\setstretch{1}#2\medskip}}
\makeatother

\begin{document}

\noindent Solve the following equations:
\begin{tasks}(3)
\task Equation $1$
 \task Equation $2$
 \task Equation $3$
 \task Equation $4$ is a rather long equation
 \task Equation $5$
 \task Equation $6$
 \task Equation $7$
 \task Equation $8$
\end{tasks}
\bigskip

\noindent Solve the following equations:
\begin{tabenumerate}
  \item Equation $1$
\item Equation $2$
\item Equation $3$
\item Equation $4$ is a rather long equation
\item Equation $5$
\paritem[1] {Equation $6$ is another long equation}
\paritem[2] {Equation $7$ is a third long equation that stretches along two columns. }
\item Equation $8$

\end{tabenumerate}

\end{document}