Henry Ernest Dudeney/Puzzles and Curious Problems/261 - The Twenty-Two Bridges/Solution

by : $261$

 * The Twenty-Two Bridges

Solution
$C$ and $L$.

Proof
Each department has an even number of bridges leading from it, except $C$ and $L$, which have $3$.

The underlying graph of this map is therefore traversable.

From Characteristics of Traversable Graph it follows that $C$ and $L$ are the start and end points.

Hence the result.