Edexcel FD2 AS 2021 June — Question 2

Exam BoardEdexcel
ModuleFD2 AS (Further Decision 2 AS)
Year2021
SessionJune
TopicNetwork Flows

2. \begin{figure}[h]
\includegraphics[alt={},max width=\textwidth]{261e22b8-0063-419c-a388-6831a427fb65-03_860_1705_276_182} \captionsetup{labelformat=empty} \caption{Figure 1}
\end{figure} Figure 1 shows a capacitated, directed network. The number on each arc represents the capacity of that arc. The numbers in circles represent an initial flow.
  1. State the value of the initial flow.
    (1)
  2. Obtain the capacity of the cut that passes through the arcs \(\mathrm { AG } , \mathrm { CG } , \mathrm { GF } , \mathrm { FT } , \mathrm { FH }\) and EH .
    (1)
  3. Complete the initialisation of the labelling procedure on Diagram 1 in the answer book by entering values along \(\mathrm { SD } , \mathrm { BD } , \mathrm { BE }\) and GF .
    (2)
  4. Use the labelling procedure to find a maximum flow through the network. You must list each flow-augmenting route you use, together with its flow.
    (3)
  5. Use the answer to part (d) to add a maximum flow pattern to Diagram 2 in the answer book.
    (1)
  6. Prove that your answer to part (e) is optimal.
    (3)