Edexcel FD2 2024 June — Question 1

Exam BoardEdexcel
ModuleFD2 (Further Decision 2)
Year2024
SessionJune
TopicNetwork Flows

1. \begin{figure}[h]
\includegraphics[alt={},max width=\textwidth]{931ccf1d-4b02-448c-b492-846b0f42c057-02_696_1347_214_367} \captionsetup{labelformat=empty} \caption{Figure 1}
\end{figure} Figure 1 shows a capacitated, directed network of pipes. The numbers in circles represent an initial flow from S to T . The other number on each arc represents the capacity, in litres per second, of the corresponding pipe.
    1. State the value of \(x\)
    2. State the value of \(y\)
  1. State the value of the initial flow.
  2. State the capacity of cut \(C _ { 1 }\)
  3. Find, by inspection, a flow-augmenting route to increase the flow by four units. You must state your route. The flow-augmenting route from (d) is used to increase the flow from S to T .
  4. Prove that the flow is now maximal. A vertex restriction is now applied so that no more than 12 litres per second can flow through E.
    1. Complete Diagram 1 in the answer book to show this restriction.
    2. State the value of the maximum flow through the network with this restriction.