162 Combinatorial & Topological Problems
the reverse way of a route as different. There is a tunnel between Nand 0,
and another between Rand S, and the good lady objects very much to going
through these. She also wants to delay her visit to D as long as possible in order
to meet the convenience of a friend who resides there. The puzzle is to show
Mrs. Simper her very best route in these circumstances.- SIXTEEN STRAIGHT RUNS
A commercial traveller started in his car from the point shown, and wished
to go 76 miles in sixteen straight runs, never going along the same road twice.
The dots represent towns and villages, and these are one mile apart. The lines
show the route he selected. It will be seen that he carried out his plan correctly,
but six towns or villages were unvisited.- • •
- •
Can you show a better route by which he could have gone 76 miles in six-
teen straight runs, and left only three towns unvisited?
- PLANNING TOURS
The illustration represents a map (considerably simplified for our purposes)
of a certain district. The circles are towns and villages, and the lines roads.
Can you show how five automobile drivers can go from A to A, from B to B,