Edexcel D1 — Question 4

Exam BoardEdexcel
ModuleD1 (Decision Mathematics 1)
TopicGraph Theory Fundamentals

4. \begin{figure}[h]
\includegraphics[alt={},max width=\textwidth]{acc09687-11a3-4392-af17-3d4d331d5ab4-05_501_493_196_529} \captionsetup{labelformat=empty} \caption{Fig. 3}
\end{figure} Figure 3 shows the graph \(K _ { 4 }\).
  1. State the features of the graph that identify it as \(K _ { 4 }\).
  2. In \(K _ { 4 }\), the Hamiltonian cycles \(A B C D A , B C D A B , C D A B C\) and \(D A B C D\) are usually regarded as being the same cycle. Find the number of distinct Hamiltonian cycles in
    1. \(\quad K _ { 4 }\),
    2. \(K _ { 5 }\),
    3. \(K _ { 10 }\).
  3. In a weighted network, 8 possible routes must be placed in ascending order according to their lengths. The routes have the following lengths in kilometres: $$\begin{array} { l l l l l l l l } 27 & 25 & 29 & 32 & 19 & 24 & 17 & 26 \end{array}$$ Use a quick sort to obtain the sorted list, giving the state of the list after each comparison and indicating the pivot elements used.