OCR D2 — Question 4

Exam BoardOCR
ModuleD2 (Decision Mathematics 2)
TopicNetwork Flows

  1. A sheet is provided for use in answering this question.
\begin{figure}[h]
\includegraphics[alt={},max width=\textwidth]{89e3545e-fa4b-47dd-8651-7c8f998df9e7-3_725_1303_274_340} \captionsetup{labelformat=empty} \caption{Fig. 2}
\end{figure} Figure 2 above shows a capacitated, directed network. The number on each arc indicates the capacity of that arc.
  1. Calculate the values of cuts \(C _ { 1 }\) and \(C _ { 2 }\).
  2. Find the minimum cut and state its value. \begin{figure}[h]
    \includegraphics[alt={},max width=\textwidth]{89e3545e-fa4b-47dd-8651-7c8f998df9e7-3_645_1316_1430_338} \captionsetup{labelformat=empty} \caption{Fig. 3}
    \end{figure} Figure 3 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.