How to arrange a page as two colum? (similar to multicols)

Question

There a some math problems& answers, I want to show them in two columns as following:

But I have no idea how to implement this function.

I have tried tabular and multicols, however these commands didn't work as I expected.

Any help would be appreciated!

Answer 1

I believe this might work. We put two minipages on a line, the code is different from left(=odd, we start a paragraph there) and right(=even, we make a horizontal space before and vertical space after) Q&A

I hope that the usage is clear. We added \raggedbottom to allow the pages to be underfull.

\documentclass{article}

\raggedbottom

\newcounter{QA}
\newcommand\QA[2]{
  \refstepcounter{QA}
  \ifodd\arabic{QA}
    \par\noindent\begin{minipage}[t]{0.47\textwidth}
  \else
    \hspace{0.06\textwidth}\begin{minipage}[t]{0.47\textwidth}
  \fi
  \textsf{\bfseries Q\arabic{QA}:}\hspace{0.3em plus 0.2em minus 0.1em}\ignorespaces#1
  \smallskip\par
  \textsf{\bfseries A\arabic{QA}:}\hspace{0.3em plus 0.2em minus 0.1em}\ignorespaces#2
  \ifodd\arabic{QA}
    \end{minipage}\ignorespaces
  \else
    \hspace{0.06\textwidth}\end{minipage}
    \bigskip\par
  \fi
}

\begin{document}

\QA{
  Why $42$?
  }{
  Because $42=\int_0^{42}1 dx$.
  Because $42=\int_0^{42}1 dx$.
  Because $42=\int_0^{42}1 dx$.
  Because $42=\int_0^{42}1 dx$.
  Because $42=\int_0^{42}1 dx$.
  Because $42=\int_0^{42}1 dx$.
}
%
\QA{
  Why $43$?
  }{
  Because it is a prime number.
}
%
\QA{
Why $44$?
}{
Because it is a palindrome.
}

\end{document}