1. The citizens of the Scandinavian town of Garnsholm are trying to solve a puzzle: is it possible to take a

wundertur, that is, a cycle ride through Garnsholm that crosses each of its seven bridges exactly once?

(Note that a wundertur does not have to start and end at the same point).

North Island

B

South Island

M

(a) [3 marks]. Turn this map of Garnsholm into a graph, and find its degree sequence. Is this graph

simple?

(b) [4 marks]. Explain why there can be no wundertur through Garnsholm. (You can assume any

results we proved in the lectures, but you should state what they are.)

(c) [3 marks]. The citizens of South Island are so annoyed by your argument that they decide to

demolish one of the three bridges connecting them to the rest of Garnsholm. Indicate on your

graph which of the bridges they could choose to remove if they want to make it possible to take a

wundertur. Give a brief justification.