Edexcel D1 — Question 6

Exam BoardEdexcel
ModuleD1 (Decision Mathematics 1)
TopicNetwork Flows

6. This question should be answered on the sheet provided. \begin{figure}[h]
\includegraphics[alt={},max width=\textwidth]{6c6b7934-ab46-4a87-8a11-f99bf9a5d743-06_723_1292_276_349} \captionsetup{labelformat=empty} \caption{Fig. 4}
\end{figure} Figure 4 above shows a capacitated, directed network. The number on each arc indicates the capacity of that arc.
  1. Calculate the values of cut \(C _ { 1 }\) and \(C _ { 2 }\).
  2. Find the minimum cut and state its value.
    (2 marks) \begin{figure}[h]
    \includegraphics[alt={},max width=\textwidth]{6c6b7934-ab46-4a87-8a11-f99bf9a5d743-06_647_1303_1430_347} \captionsetup{labelformat=empty} \caption{Fig. 5}
    \end{figure} Figure 5 shows a feasible flow through the same network.
  3. State the values of \(x , y\) and \(z\).
  4. Using this as your initial flow pattern, use the labelling procedure to find a maximal flow. You should list each flow-augmenting route you use together with its flow. State how you know that you have found a maximal flow.
    (8 marks)