Two friends were spending their bank holiday on a cycling trip. Stopping
for a rest at a village inn, they consulted a route map, which is
represented in our illustration in an exceedingly simplified form, for
the puzzle is interesting enough without all the original complexities.
They started from the town in the top left-hand corner marked A. It will
be seen that there are one hundred and twenty such towns, all connected
by straight roads. Now they discovered that there are exactly 1,365
different routes by which they may reach their destination, always
travelling either due south or due east. The puzzle is to discover which
town is their destination.
[Illustration]
Of course, if you find that there are more than 1,365 different routes
to a town it cannot be the right one.