AQA D1 2007 June — Question 3

Exam BoardAQA
ModuleD1 (Decision Mathematics 1)
Year2007
SessionJune
TopicShortest Path

3 [Figure 1, printed on the insert, is provided for use in this question.]
The following network represents the footpaths connecting 12 buildings on a university campus. The number on each edge represents the time taken, in minutes, to walk along a footpath.
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    1. Use Dijkstra's algorithm on Figure 1 to find the minimum time to walk from \(A\) to \(L\).
    2. State the corresponding route.
  1. A new footpath is to be constructed. There are two possibilities:
    from \(A\) to \(D\), with a walking time of 30 minutes; or from \(A\) to \(I\), with a walking time of 20 minutes. Determine which of the two alternative new footpaths would reduce the walking time from \(A\) to \(L\) by the greater amount.
    (3 marks)