AQA D1 2009 January — Question 6 7 marks

Exam BoardAQA
ModuleD1 (Decision Mathematics 1)
Year2009
SessionJanuary
Marks7
PaperDownload PDF ↗
TopicMinimum Spanning Trees
TypeMST bounds or theoretical limits
DifficultyChallenging +1.2 This question requires understanding MST properties and graph construction rather than just algorithm application. Part (a) is straightforward (sum 4 smallest edges), but parts (b) and (c) demand insight into which edge configurations are possible for a 5-vertex graph and constructing a valid example—going beyond routine Kruskal's/Prim's algorithm application typical at this level.
Spec7.02b Graph terminology: tree, simple, connected, simply connected7.04b Minimum spanning tree: Prim's and Kruskal's algorithms

6 A connected graph \(G\) has five vertices and has eight edges with lengths \(8,10,10,11,13,17\), 17 and 18.
  1. Find the minimum length of a minimum spanning tree for \(G\).
  2. Find the maximum length of a minimum spanning tree for \(G\).
  3. Draw a sketch to show a possible graph \(G\) when the length of the minimum spanning tree is 53 .

6 A connected graph $G$ has five vertices and has eight edges with lengths $8,10,10,11,13,17$, 17 and 18.
\begin{enumerate}[label=(\alph*)]
\item Find the minimum length of a minimum spanning tree for $G$.
\item Find the maximum length of a minimum spanning tree for $G$.
\item Draw a sketch to show a possible graph $G$ when the length of the minimum spanning tree is 53 .
\end{enumerate}

\hfill \mbox{\textit{AQA D1 2009 Q6 [7]}}