Am 09.01.2014 um 18:36 schrieb Otared Kavian <otared@gmail.com>:

Hi Wolfgang, Hi Aditya,

Thanks for your attention.
Unfortunately adding 
\keepblocks[question] 
the example I sent before does not work in mkiv, and changing 
location=hanging
to
alternative=hanging
does not help neither…
The error message in mkiv is:
\dostopnormalblock ...meter \c!after \par \egroup 
                                                  
<argument> ...fact that $2\times 5 = 10$. \dostopnormalblock 
                                                  \dostartnormalblock {hint}...
\dodowithpar ...dler \v!construction \endcsname #1
                                                  \csname \??constructionsto…

So I don’t know what to do if one has to use mkiv.

When you enumerations in this form

\beginanswer
\answer $10$
\endanswer

you have to finish the paragraph, e.g. by adding \par

\beginanswer
\answer $10$\par
\endanswer

or better use the start/stop commands for the enumeration.

\beginanswer
\startanswer
$10$
\stopanswer
\endanswer

Wolfgang