\documentclass[11pt]{article}
\usepackage{amsmath, amsthm, amssymb, amsthm, units, full page}
\usepackage{longtable}

\newcounter{prob_num}
\setcounter{prob_num}{1}
\newcommand{\prob}{\arabic{prob_num})  \stepcounter{prob_num}}

\begin{document}


\begin{tabular}{lr}
	Name:\underline{\hspace{8cm}}  & Math 095 Quiz 1 \\
	& \hspace{3cm} 9 June 2011
\end{tabular}

\textbf{Solve.} (30 points)
\vspace{.25cm}\\

\begin{longtable}{p{5cm}p{5cm}p{5cm}}
\vspace{3cm}
\prob  $r+c=b$ for $c$&
\prob  $ay=m$ for $a$&
\prob  $a-b=c$ for $b$\\
\vspace{3cm}
\prob  $\frac{a}{b}=y$ for $b$&
\prob  $a=c(x-y)$ for $c$&
\prob  $ax+m=c$ for $a$\\
\end{longtable}

\textbf{Write a formula to describe the value.} (10 points)
\vspace{.25cm}\\

\prob A race is run around a lake.  Bob and Charles run it as a relay while Allison runs the whole course alone.  Find the distance Bob ran ($b$) in terms of the distances run by Charles and Allison ($c$ and $a$ respectively).
\vspace{3cm}\\

\textbf{Perform the given operation.} (10 points)
\vspace{.25cm}\\

\begin{longtable}{p{7.5cm} p{7.5cm}}
\prob $\frac{a}{b}+\frac{x}{y}$ &
\prob $\frac{a}{b}\frac{x}{y}$\\
\end{longtable}

\end{document}