\documentclass[11pt]{article}

\setlength{\oddsidemargin}{0in}
\setlength{\evensidemargin}{0in}
\setlength{\topmargin}{0.0in}
\setlength{\headheight}{0in}
\setlength{\headsep}{0in}
\setlength{\textwidth}{6.5in}
\setlength{\textheight}{9.0in}
\setlength{\parindent}{0in}
\setlength{\parskip}{0.1in}
\setlength{\columnseprule}{0.4pt}

\usepackage{times}

\begin{document}

% \begin{equation}
% a \leq b
% \end{equation}

% \begin{equation}
% \frac{a}{b+c}
% \end{equation}

\begin{equation}
\frac{d}{dt} E(t^X) = E(Xt^{X-1})
\end{equation}
\end{document}