How to get Example and solution as in the style of the attached jpg file

Question

How to get Example and solution as in the style with boundaries of the attached jpg file.

  \documentclass{book}
\usepackage{graphicx,amssymb,amsmath}
\usepackage{exercise,chngcntr}
\counterwithin{Exercise}{chapter}
\counterwithin{Answer}{chapter}
\renewcounter{Exercise}[chapter]
\renewcommand{\theExercise}{\thechapter.\arabic{Exercise}}
\begin{document}
\begin{Exercise}
Prove that $    \frac{1}{2}\Delta(f_{ij}f^{ij}) =\nabla^{k}f^{ij}+f^{ij}f^{k}[2 \nabla_{i}R_{jk}-\nabla_{k}R_{ij}]$
\end{Exercise}
\begin{Answer}
Answer 2.2
        \end{Answer}
  \end{document}

@CarLaTeX I am a layman in Latex. Please help me so that I can get automatic Example numbering and Solution after the question with the style as I have attached above. Thanks. — user1942348, May 10 '17 at 14:10
@user1942348 Do you want the example numbered without the number of the chapter and the solution without number? — CarLaTeX, May 10 '17 at 15:14
maybe as a starting point: https://tex.stackexchange.com/a/254351/36296 or https://tex.stackexchange.com/a/254425/36296 — samcarter_is_at_topanswers.xyz, May 10 '17 at 15:22
@CarLaTeX It will be better if I can write ex no according as chapter and solution without no. — user1942348, May 10 '17 at 16:51

CarLaTeX · Accepted Answer · 2017-05-11T07:06:45.857

I've created the new environment Example which puts the Exercise one within a tcolorbox.

\documentclass{book}
\usepackage{graphicx,amssymb,amsmath}
\usepackage[lastexercise]{exercise}
\usepackage{chngcntr}
\usepackage{xcolor}
\usepackage{tcolorbox}
\tcbset{arc=0mm,boxrule=1pt,colback=white,colframe=cyan,leftrule=3mm}

\counterwithin{Exercise}{chapter}
\counterwithin{Answer}{chapter}
\renewcounter{Exercise}[chapter]
\renewcommand{\theExercise}{\thechapter.\arabic{Exercise}}
\renewcommand{\AnswerHeader}{\medskip\noindent\textcolor{red}{\textbf{SOLUTION}}\;}
\renewcommand{\ExerciseName}{EXAMPLE}
\renewcommand{\ExerciseHeader}{\noindent\textbf{\ExerciseName\;\ExerciseHeaderNB}}
\newenvironment{Example}{\begin{tcolorbox}\begin{Exercise}}{\end{Exercise}\end{tcolorbox}}
\setlength{\ExerciseSkipBefore}{0pt}
\setlength{\AnswerSkipAfter}{\baselineskip}
\begin{document}
    \chapter{My first set of exercises}
    \begin{Example}
        Prove that $\frac{1}{2}\Delta(f_{ij}f^{ij}) =\nabla^{k}f^{ij}+f^{ij}f^{k}[2\nabla_{i}R_{jk}-\nabla_{k}R_{ij}]$
    \end{Example}
    \begin{Answer}
        From \dots
    \end{Answer}

    \begin{Example}
        Prove that Paulinho is smart.
    \end{Example}
    \begin{Answer}
        All ducks are smart. Paulinho is a duck. Therefore, Paulinho is smart.
    \end{Answer}

    \begin{Example}
        Prove that Paulinho is smart.
    \end{Example}
    \begin{Answer}
        All ducks are smart. Paulinho is a duck. Therefore, Paulinho is smart.
    \end{Answer}

    \chapter{My second set of exercises}
    \begin{Example}
        Prove that Paulinho is smart.
    \end{Example}
    \begin{Answer}
        All ducks are smart. Paulinho is a duck. Therefore, Paulinho is smart.
    \end{Answer}

    \begin{Example}
        Prove that Paulinho is smart.
    \end{Example}
    \begin{Answer}
        All ducks are smart. Paulinho is a duck. Therefore, Paulinho is smart.
    \end{Answer}
\end{document}

I hope this is the output you are looking for:

score 3 · Answer 2 · answered Jun 01 '17 at 08:21

Using the xsim package with tcolorbox (questions and answers stolen from CarLaTeX's answer):

\documentclass{article}
\usepackage{xsim,tcolorbox,needspace}

\xsimsetup{
  exercise/within = section ,
  exercise/the-counter = \thesection.\arabic{exercise} ,
  exercise/template = cyan-box ,
  exercise/name = Example ,
  solution/template = red ,
  solution/print = true
}

\DeclareExerciseEnvironmentTemplate{cyan-box}
  {%
    \begin{tcolorbox}[arc=0mm,boxrule=1pt,colback=white,colframe=cyan,leftrule=3mm]
      \textsf{%
        \MakeUppercase{%
          \XSIMmixedcase{\GetExerciseName}~\GetExerciseProperty{counter}%
        }%
      }%
      \GetExercisePropertyT{subtitle}{ \textit{#1}}%
      \quad
  }
  {\end{tcolorbox}}

\DeclareExerciseEnvironmentTemplate{red}
  {%
    \par
    \Needspace*{2\baselineskip}
    \noindent
    \textsf{\textcolor{red}{\MakeUppercase{\XSIMmixedcase{\GetExerciseName}}}}%
    \quad
  }
  {\par\bigskip}

\begin{document}

\section{My first set of exercises}
\begin{exercise}
  Prove that $\frac{1}{2}\Delta(f_{ij}f^{ij})
  =\nabla^{k}f^{ij}+f^{ij}f^{k}[2\nabla_{i}R_{jk}-\nabla_{k}R_{ij}]$
\end{exercise}
\begin{solution}
  From \dots
\end{solution}

\begin{exercise}
  Prove that Paulinho is smart.
\end{exercise}
\begin{solution}
  All ducks are smart. Paulinho is a duck. Therefore, Paulinho is smart.
\end{solution}

\begin{exercise}
  Prove that Paulinho is smart.
\end{exercise}
\begin{solution}
  All ducks are smart. Paulinho is a duck. Therefore, Paulinho is smart.
\end{solution}

\section{My second set of exercises}
\begin{exercise}
  Prove that Paulinho is smart.
\end{exercise}
\begin{solution}
  All ducks are smart. Paulinho is a duck. Therefore, Paulinho is smart.
\end{solution}

\begin{exercise}
  Prove that Paulinho is smart.
\end{exercise}
\begin{solution}
  All ducks are smart. Paulinho is a duck. Therefore, Paulinho is smart.
\end{solution}

\end{document}

FYI xsim throws an error in Miktex:
("C:\Program Files\MiKTeX 2.9\tex/latex/xsim\xsim.random.code.tex") ! Undefined control sequence. \xsim_declare_translation:nnn ...claretranslation {#1}{\c__xsim_keyword_pref... l.357 Happens even with the latest Miktex updates. — rhody, Dec 30 '20 at 18:58
Problem solved, I had an old translation.sty file that was wasn't updated. — rhody, Dec 30 '20 at 19:08

How to get Example and solution as in the style of the attached jpg file

2 Answers2