The Five Regiments

A simplified map of a wartime district: circles are towns, lines are roads. On the same night, five regiments each marched from one labeled town to its twin — upper A to lower A, upper B to lower B, and so on through E — yet no regiment ever saw another.

1. Five pairs of towns are marked A through E, each pair joined only indirectly through the shared road network.
2. Every regiment must reach its twin town the same night.
3. No two regiments may use the same road, anywhere on the map, even briefly.

Can you route all five regiments so that no two ever share a stretch of road?

Reveal the answer

Yes — Henry Dudeney's own solution threads all five routes through the network so that every pair of towns connects without any two regiments' paths ever overlapping on a single road.