\problemdata                                                             
        {Married Couples} % latex-friendly label for the prob.
        {Expectation} % The topic(s) of the problem content.  
        {from ``A first course in Probability" p92, exercises 3 and 9} % Source (if known)                                          
        {S01 Final, 12} % Usage (list ones you are aware of). 
        {Tina Wang, S02} % Last revision info (author, date).   
                                                                         
                                                                         
\begin{problem} 
\begin{problemparts}          
Twenty individuals, consisting of 10 married couples, are to be seated
at 5 different tables, with 4 people at each table.

\problempart If the seating is done ``at random", what is the expected
number of married couples that are seated at the same table?

\problempart If two men and two women are randomly chosen to be seated
at each table, what is the expected number of married couples that are
seated at the same table?

\problempart Now, suppose that those 20 people are going to be seated
at \emph{seven} tables, 3 of which have 4 seats and 4 of which have 2
seats. If the people are randomly seated, find the expected value of
the number of married couples that are seated at the same table.

\end{problemparts}
\end{problem}
                                 