370 Answers- SIXTEEN STRAIGHT RUNS
The illustration shows how the traveller could have driven his car 76 miles
in sixteen straight runs and left only three towns unvisited. This is not an easy
puzzle, and the solution is only to be found after considerable trial.~
[Victor Meally improved this answer by finding a 76-mile, l6-segment path
that leaves only one town unvisited. It is believed to be the best possible solu-
tion. The reader may enjoy searching for it.-M. G.]- PLANNING TOURS
In our illustration, in which the roads not used are omitted for the sake of
clearness, every man's route is shown. It will be seen that no two drivers ever
go along the same road, and that no man ever crosses the track of another.
Although no hard-and-fast rules can be laid down for the solution of puzzles
in this particular class, a little careful thought will generally overcome our
difficulties. For example, we showed in the puzzle that if A goes direct to A
in a straight line, we shall hopelessly cut off C, D, and E. It soon becomes
evident that A must go to the left of the upper D, and having done so, must