The Island of Tetra.

For those of you who did the Maths Competition paper last week with the last question being about the island of  Tetra, remember how we all took a guess and wasted time drawing maps on our one regulation sheet of working paper?

This smart guy has figured it out;

Q - There are so many towns on the island of Tetra, all connected by roads. Each town has three roads leading to three other different towns: one red road, one yellow road and one blue road, where no two roads meet other than at towns. If you start from any town and travel along red and yellow roads alternately (RYRY...) you will get back to your starting town after having travelled over six different roads. In fact RYRYRY will always get you back to where you started. In the same way, going along yellow and blue roads alternately will always get you back to the starting point after travelling along six different roads (YBYBYB). On the other hand, going along red and blue roads alternately will always get you back to the starting point after travelling along four different roads (RBRB). How many towns are there on Tetra?



Solution;


24 Towns.

Thank you to: Matthew Stoneham
EDIT; And Anonymous 

Now I don't know what you guys put as the answer, but I put 7 ... so ... EDIT; Not so ... close ...