Answers 359in eighteen moves. It is absolutely necessary to include the stage marked
"Irish Sea" in order to perform the journey in an even number of stages.
- MARKING A TENNIS COURT
The ten points lettered in the illustration are all "odd nodes," that is points
from which you can go in an odd number of directions-three. Therefore we
know that five lines (one-half of 10) will be required to draw the figure. The
A'r---.8",:r---------,.C-.-.-... --· -D
.
!
:
E~:---------------~F· • •
G ~ ••••••••• ~~ _____________ ~:.:...7 ____ __4IKdotted lines will be the four shortest possible between nodes. Note that you
cannot here use a node twice or it would be an improvement to make