problem tag is used to present a
question or task to the reader. The
problem and optional
solution tags appear inside the
exercise tag to present a question or task and an
answer, respectively, to the reader.
<exercise id="problemexample">
<problem>
<para id="prob_1">
What is the capital of Texas?
</para>
</problem>
<solution>
<para id="sol_1">
Austin is the capital of Texas.
</para>
</solution>
</exercise>