%大問2の Kaitou環境内に \inputHakoKaiFile を記述します。

% --- re4544.tex -----------------------------------
\documentclass[a4p,12pt]{jarticle}
%\usepackage{emath}%%%%%%%%%%%%%%%%%%% 不要
\usepackage{hako}
\usepackage{emathAe}
\pagestyle{plain}

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\begin{document}
\begin{enumerate}
\openKaiFile
 \item aaaa
   \begin{Kaitou} answer1 \end{Kaitou}
%\closeKaiFile%%%%%%%%%%%%%%%%%%%%%%%%  ここでは閉じる必要なし
\hakosyokika
\openHakoKaiFile%%%%%%%%%%%%%%%%%%%%%%  HakoKaiFile は1問ずつ open, close を繰り返す
 \item \Hako'bbb'
\closeHakoKaiFile %%%%%%%%%%%%%%%%%%%%
        \begin{Kaitou}
                \inputHakoKaiFile%%%%%%%%%%%%%%%%% Kaitou環境内で HakoKaiFile を読み込む

                必要なら，解説など。
\end{Kaitou}
%\openKaiFile%%%%%%%%%%%%%%%%%%%%%%%%
 \item cccc
   \begin{Kaitou} answer3 \end{Kaitou}
\closeKaiFile
\end{enumerate}
\vfill
%\input{hakokaiとkaifile.k1}%%%%%%%%% 1〜3 の解答は一つのファイルになっています。
%\inputHakoKaiFile
%\input{hakokaiとkaifile.k2}

\inputKaiFile

\end{document}

▼関連発言
│
└◆4544:KaiFileとHakoKaiFileの共存 [マッカマン] 04/05 11:44
　└◆4545:Re:KaiFileとHakoKaiFileの共存 [tDB] 04/05 12:46
　　└◆4546:Re[2]:KaiFileとHakoKaiFileの共存 [マッカマン] 04/05 14:22<-last