
\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}{0.15in}

\usepackage{times}
\usepackage{url}
\usepackage{graphicx}

\usepackage{listings}

\begin{document}

\title{Chapter 1}

\author{}

\date{}

\maketitle

\textbf{1.} Rather complicated problem, but not bad if one is
persistent.  The probability in question is $P(L_2 = 1 | A_1 = 0$, where
$A_j$ is the number who alight at stop j.  One must then evaluate
$P(L_2 = 1 \textrm{ and } A_1 = 0)$ and $P(A_1 = 0$, by enumerating the
various probabilities.

\textbf{2.} Straightforward appilication of the mailing tubes.

\textbf{3.} Straightforward appilication of the mailing tubes.

\textbf{4.} No need for the mailing tubes here.  To find $P(S = 12 | T =
2)$, note that $T = 2$ means one of the pairs (1,1), (2,2),...,(6,6).
All are equally likely, so the conditional probability is 1/6.  The
opposite probability is 1.

\end{document}


