\documentclass[letter, 12pt]{article}
\usepackage[margin=1in]{geometry}
\usepackage{url}
\usepackage{graphicx}
\pagenumbering{arabic}
\pagestyle{plain}

\begin{document}
\renewcommand{\theenumi}{\arabic{enumi}}
\renewcommand{\labelenumi}{{\theenumi}.}
\renewcommand{\theenumii}{\alph{enumii}}
\renewcommand{\labelenumii}{(\theenumii)}

\begin{flushright}
Math 165 Assignment \#1\\
Your name\\
Date\\
\end{flushright}

\begin{enumerate}
\item What are the three roots of the equation $z^3=1$?\\

Here is the answer.
\end{enumerate}
\end{document}