6.

\begin{figure}[h]
\begin{center}
  \includegraphics[alt={},max width=\textwidth]{89702b66-cefb-484b-9c04-dd2be4fe2250-07_688_1351_203_356}
\captionsetup{labelformat=empty}
\caption{Figure 3}
\end{center}
\end{figure}

[The total weight of the network is 315]\\
Figure 3 represents a network of roads between nine parks, A, B, C, D, E, F, G, H and J. The number on each edge represents the length, in miles, of the corresponding road.
\begin{enumerate}[label=(\alph*)]
\item \begin{enumerate}[label=(\roman*)]
\item Use Dijkstra's algorithm to find the shortest path from A to J.
\item State the length of the shortest path from A to J .

The roads between the parks need to be inspected. Robin must travel along each road at least once. Robin wishes to minimise the length of the inspection route. Robin will start the inspection route at C and finish at E .
\end{enumerate}\item By considering the pairings of all relevant nodes, find the length of Robin's route.
\item State the number of times Robin will pass through G .

It is now decided to start and finish the inspection route at A. Robin must still minimise the length of the route and travel along each road at least once.
\item Calculate the difference between the lengths of the two inspection routes.
\item State the edges that need to be traversed twice in the route that starts and finishes at A , but do not need to be traversed twice in the route that starts at C and finishes at E .
\end{enumerate}

\hfill \mbox{\textit{Edexcel D1 2023 Q6 [13]}}