1 The directed bipartite graph represents links between chairlifts and ski runs in one part of a ski resort. Chairlifts are represented by capital letters, and ski runs are represented by numbers. For example, chairlift A takes skiers to the tops of ski runs 1 and 2, whereas ski run 2 takes skiers to the bottom of chairlift B .
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1. The incomplete map in your answer book represents the three chairlifts and ski run 2 . Complete the map by drawing in the other 4 ski runs. Angus wants to ski all 5 ski runs, starting and finishing at the bottom of chairlift A .
2. Which chairlifts does Angus have to repeat, and why?
3. Which ski runs does Angus have to repeat, and why? The chairlifts and ski runs shown above form only part of the resort. In fact, chairlift C also takes skiers to the bottom of chairlift \(D\).
4. Why can this information not be represented in a bipartite graph?