Cfrgtkky

documentclass[a4paper,11pt]{book}

usepackage{hyperref}

usepackage[lastexercise,answerdelayed,exercisedelayed]{exercise}

renewcommand{AnswerName}{Exercise}





begin{document}

{





tableofcontents

mainmatter



chapter{Classical physics}

section*{The good old days}

For every $epsilon>0$

begin{Exercise}[label={afaff}, name={Exercice}, difficulty={1}]

sfsf

end{Exercise}

begin{Answer}

aggsg f

end{Answer}





chapter{Modern physics}

section*{Departure from classical physics}

There exists a $delta>0$

begin{Exercise}[label={dghd}, name={Exercice}, difficulty={2}]

b7dyfas789

end{Exercise}

begin{Answer}

hjsdgfkihsk 

end{Answer}





chapter{Neoclassical physics}

section{Guess who's back}

begin{Exercise}[label={NQCD}, name={Exercice}, difficulty={3}]

skjhfkshf

end{Exercise}

begin{Answer}

b78asghfkighkia

end{Answer}





part{Exercises}

shipoutExercise



part{Solutions}

shipoutAnswer





end{document}

In the last two parts, the exercises are shown without any reference to the chapters. How can I make them like this:

Chaptername

its exercises

chaptername

its exercises

etc

Maybe you would like to number to exercises within chapters.

I've used xassoccnt to print the total number of exercises.

I've modified ExerciseHeader and AnswerHeader to print the Chapter number and name before its exercises when you ship out them.

documentclass[a4paper,11pt]{book}

usepackage[lastexercise,answerdelayed,exercisedelayed]{exercise}

renewcommand{ExerciseName}{Exercice}

renewcommand{AnswerName}{Exercice}

usepackage{totcount}

regtotcounter{Exercise} % register the counter for getting the total

usepackage{chngcntr}

counterwithin{Exercise}{chapter}

counterwithin{Answer}{chapter}

usepackage{xassoccnt}

NewTotalDocumentCounter{totalex}

usepackage{titleref}

usepackage{etoolbox}

renewcommand{ExerciseHeader}{ stepcounter{totalex}ifnumcomp{value{Exercise}}{=}{1}{ifnumcomp{thechapter}{=}{1}{}{vspace{10pt}}noindentLargetextbf{Chapter thechapter currenttitle}parvspace{10pt}}{}noindentnormalsizebfseriesExerciseName ExerciseHeaderNB ExerciseHeaderDifficultyparmedskip}

renewcommand{AnswerHeader}{ifnumcomp{value{Exercise}}{=}{1}{ifnumcomp{thechapter}{=}{1}{}{vspace{10pt}}noindentLargetextbf{Chapter thechapter currenttitle}parvspace{10pt}}{}noindentnormalsizebfseriesAnswerName ExerciseHeaderNB ExerciseHeaderDifficultyparmedskip}



usepackage{hyperref}



begin{document}

This document contains TotalValue{totalex} solved exercises.



tableofcontents

mainmatter



chapter{Classical physics}

makeatletter



makeatother

section*{The good old days}

For every $epsilon>0$

begin{Exercise}[label={afaff}, difficulty={1}]

sfsf

end{Exercise}

begin{Answer}

aggsg f

end{Answer}

begin{Exercise}[difficulty={2}]

another exercise

end{Exercise}

begin{Answer}

another answer

end{Answer}

begin{Exercise}[difficulty={1}]

one more exercise

end{Exercise}

begin{Answer}

one more answer

end{Answer}

chapter{Modern physics}

section*{Departure from classical physics}

There exists a $delta>0$

begin{Exercise}[label={dghd}, difficulty={2}]

b7dyfas789

end{Exercise}

begin{Answer}

hjsdgfkihsk 

end{Answer}



chapter{Neoclassical physics}

section{Guess who's back}

begin{Exercise}[label={NQCD}, difficulty={3}]

skjhfkshf

end{Exercise}

begin{Answer}

b78asghfkighkia

end{Answer}



part{Exercises}

shipoutExercise



part{Solutions}

shipoutAnswer



end{document}