Edexcel D1 2011 January — Question 1 8 marks

Exam BoardEdexcel
ModuleD1 (Decision Mathematics 1)
Year2011
SessionJanuary
Marks8
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicShortest Path
TypeBasic Dijkstra's algorithm application
DifficultyModerate -0.8 This is a straightforward application of Dijkstra's algorithm, a standard D1 procedure that students practice extensively. Part (a) requires mechanical execution of the algorithm (5 marks for showing working), parts (b) and (c) are direct read-offs from the completed table. No problem-solving insight or novel thinking required—purely algorithmic recall and careful arithmetic.
Spec7.04a Shortest path: Dijkstra's algorithm

1. \begin{figure}[h]
\includegraphics[alt={},max width=\textwidth]{0360f78d-e18c-4c47-a2ec-ddd705a4175f-2_750_1285_388_390} \captionsetup{labelformat=empty} \caption{Figure 1}
\end{figure} Figure 1 shows a network of roads between eight villages, \(\mathrm { A } , \mathrm { B } , \mathrm { C } , \mathrm { D } , \mathrm { E } , \mathrm { F } , \mathrm { G }\) and H . The number on each arc gives the length, in miles, of the corresponding road.
  1. Use Dijkstra's algorithm to find the shortest distance from A to H .
    (5)
  2. State your shortest route.
    (1)
  3. Write down the shortest route from H to C and state its length.
    (2)

1.

\begin{figure}[h]
\begin{center}
  \includegraphics[alt={},max width=\textwidth]{0360f78d-e18c-4c47-a2ec-ddd705a4175f-2_750_1285_388_390}
\captionsetup{labelformat=empty}
\caption{Figure 1}
\end{center}
\end{figure}

Figure 1 shows a network of roads between eight villages, $\mathrm { A } , \mathrm { B } , \mathrm { C } , \mathrm { D } , \mathrm { E } , \mathrm { F } , \mathrm { G }$ and H . The number on each arc gives the length, in miles, of the corresponding road.
\begin{enumerate}[label=(\alph*)]
\item Use Dijkstra's algorithm to find the shortest distance from A to H .\\
(5)
\item State your shortest route.\\
(1)
\item Write down the shortest route from H to C and state its length.\\
(2)
\end{enumerate}

\hfill \mbox{\textit{Edexcel D1 2011 Q1 [8]}}