Edexcel D2 Specimen — Question 4

Exam BoardEdexcel
ModuleD2 (Decision Mathematics 2)
SessionSpecimen
TopicTravelling Salesman

4. \begin{figure}[h]
\includegraphics[alt={},max width=\textwidth]{899a26d1-7599-4051-b1cf-596542624997-5_602_1255_196_406} \captionsetup{labelformat=empty} \caption{Figure 2}
\end{figure} The network in Figure 2 shows the distances, in km , of the cables between seven electricity relay stations \(A , B , C , D , E , F\) and \(G\). An inspector needs to visit each relay station. He wishes to travel a minimum distance, and his route must start and finish at the same station. By deleting C, a lower bound for the length of the route is found to be 129 km .
  1. Find another lower bound for the length of the route by deleting \(F\). State which is the best lower bound of the two.
  2. By inspection, complete the table of least distances. The table can now be taken to represent a complete network.
  3. Using the nearest-neighbour algorithm, starting at \(F\), obtain an upper bound to the length of the route. State your route.