Route & Network Puzzles 161This is a very simple proposition, but practically impossible to solve until
you have hit on some method of recording the routes. You see there are many
ways of going, from the short route ABDE, taking one of the large loops, up
to the long route ABCDBCDBCDE, which takes you over every line on the
system and can itself be varied in order in many ways. How many different
ways of going are there?
- A CAR TOUR
A man started in a car from the
town A, and wished to make a com-
plete tour of these roads, going along
every one of them once, and once
only. How many different routes are
there from which he can select? It is
puzzling unless you can devise some
ingenious method. Every route must S
end at the town A, from which you
start, and you must go straight from
town to town-never turning off at
crossroads.
- MRS. SIMPER'S HOLIDAY TOUR
The illustration represents a plan,
very much simplified, of a tour that
my friend Mrs. Simper proposes to
make next autumn. It will be seen that
there are twenty towns all connected
by lines of railways. Mrs. Simper lives
at the town marked H, and she wants
to visit everyone of the other towns
once, and once only, ending her tour
at home.
It may interest the reader to know
that there are just sixty different routes
from which she may select, counting