AQA D1 2009 January — Question 2 7 marks

Exam BoardAQA
ModuleD1 (Decision Mathematics 1)
Year2009
SessionJanuary
Marks7
PaperDownload PDF ↗
TopicMatchings and Allocation
TypeMaximum matching algorithm application
DifficultyModerate -0.8 This is a standard textbook application of the maximum matching algorithm (Hungarian algorithm or alternating path method) in bipartite graphs. Part (a) is routine matrix construction, and part (b) follows a prescribed algorithmic procedure with an initial matching provided. The question requires careful execution but no problem-solving insight or novel approach—it's testing whether students can apply a learned algorithm mechanically.
Spec7.02e Bipartite graphs: K_{m,n} notation7.02r Graph modelling: model and solve problems using graphs

2 Six people, \(A , B , C , D , E\) and \(F\), are to be allocated to six tasks, 1, 2, 3, 4, 5 and 6. The following bipartite graph shows the tasks that each of the people is able to undertake. \includegraphics[max width=\textwidth, alt={}, center]{6360ed01-76da-4265-8bc8-53ffe391704e-3_401_517_429_751} \includegraphics[max width=\textwidth, alt={}, center]{6360ed01-76da-4265-8bc8-53ffe391704e-3_408_520_943_751}
  1. Represent this information in an adjacency matrix.
  2. Initially, \(B\) is assigned to task \(1 , C\) to task \(2 , D\) to task 4, and \(E\) to task 5 . Demonstrate, by using an algorithm from this initial matching, how each person can be allocated to a task.

2 Six people, $A , B , C , D , E$ and $F$, are to be allocated to six tasks, 1, 2, 3, 4, 5 and 6. The following bipartite graph shows the tasks that each of the people is able to undertake.\\
\includegraphics[max width=\textwidth, alt={}, center]{6360ed01-76da-4265-8bc8-53ffe391704e-3_401_517_429_751}\\
\includegraphics[max width=\textwidth, alt={}, center]{6360ed01-76da-4265-8bc8-53ffe391704e-3_408_520_943_751}
\begin{enumerate}[label=(\alph*)]
\item Represent this information in an adjacency matrix.
\item Initially, $B$ is assigned to task $1 , C$ to task $2 , D$ to task 4, and $E$ to task 5 .

Demonstrate, by using an algorithm from this initial matching, how each person can be allocated to a task.
\end{enumerate}

\hfill \mbox{\textit{AQA D1 2009 Q2 [7]}}