Question

Here is a puzzle that people might find interesting. Its concept is simple but the method required is tricky to work out even though it looks easy.

You have a train going round the track in a circle. There is no locomotive, the back carriage is connected with the front carriage so if you were to move between carriages you could go in a circle forever. The diagram will illustrate this.

The lights in each carriage are either switched on or switched off (there is no pattern, it is random). You are to find a method which will lead to counting the number of carriages in the train.

Answer 1

You can only perform 2 actions:
1) Switch off/on the lights in the carriage you are in.
2) Move from one carriage to another.