Question 1.55
25. A postal worker is supposed to deliver mail on all streets represented by edges in the accompanying graph by traversing each edge exactly once. The first day, the worker traverses the numbered edges in the order shown in graph (a), but the supervisor is not satisfied—why? The second day the worker follows the path indicated in graph (b), and the worker is unhappy—why? Is the original job description realistic? Why?
25.
With part (a), not all edges are traveled by the worker. With part (b), the end of the route is not the same as the beginning of the route. The description is not realistic because there is no Euler circuit in the graph.