\documentclass[addpoints,12pt]{exam} % can add 'answers' option
\setlength{\parindent}{0mm}
\usepackage{amsmath}
\usepackage{enumerate}
\usepackage{microtype}
\usepackage{tikz}

\newcommand{\blankunderline}[2]{\makebox[#1]{#2\enspace\hrulefill}}

\newcommand{\dueday}{Tuesday}
\newcommand{\duewhen}{11/12/19 at 11:59pm}
\newcommand{\hwnum}{6}
\newcommand{\classnumber}{Math 20C -- Swanson }
\newcommand{\classiteration}{Fall 2019}

\pagestyle{headandfoot}
\runningheadrule
\firstpageheader{\classnumber -- \classiteration}{}{Homework \hwnum}
\runningheader{\classnumber}
{Homework, Page \thepage\ of \numpages}
{Due \duewhen}
\firstpagefooter{}{}{}
\runningfooter{}{}{}

\begin{document}
\ 

\begin{center}
  \fbox{\parbox{3in}{\centering\large
  \classnumber -- \classiteration \\
  Homework \hwnum \\
  Due \dueday, \duewhen}}
\end{center}
\vspace{1cm}
%\blankunderline{0.8\textwidth}{Name:}
%\blankunderline{0.15\textwidth}{Section:}

\vspace{1cm}
\begin{itemize}
  \item The graded part of the homework is on WebAssign.
  \item The problems below are also assigned and you are responsible for doing them,
    but they will not be collected or graded.
\end{itemize}

\newpage

\begin{questions}
  \question The contour plot of $z = f(x, y)$ is below.
    \begin{center}
      \includegraphics[scale=0.5]{topography.png}
    \end{center}
    \begin{enumerate}[(a)]
      \item Draw the path of steepest ascent starting at point $P$.
      \item Draw the gradient vector at point $Q$.
      \item What are the signs (positive, negative, or zero) of
        $D_{\hat\imath}f$ and $D_{\hat\jmath}f$ at point $P$?
        At point $Q$?
    \end{enumerate}
    
    \begin{solution}
      
    \end{solution}
    \newpage
\end{questions}
\end{document}