This puzzle has to do with railway routes, and in these days of much travelling should prove useful.
The map of England shows twenty-four towns, connected by a system of railways. 
A resident at the town marked A at the top of the map proposes to visit every one of the towns once and only once, and to finish up his tour at Z. 
This would be easy enough if he were able to cut across country by road, as well as by rail, but he is not. 
How does he perform the feat? 
Take your pencil and, starting from A, pass from town to town, making a dot in the towns you have visited, and see if you can end at Z.

See answer