PRIZE PUZZLE FOR JULY 2005

LINE CUTTING

The prize puzzle this month is to make a copy of the diagram on the left and then to draw a continuous red line through every line segment once and once only without crossing your own line. A "line segment" is a line that connects two junctions. You can start and finish anywhere.

Please send me, David Broughton, your sketch or GIF file by Wednesday 3rd August 2005 to be entered into the prize draw.

To contact me by email click this symbol:

To make a copy of the diagram, right click on it and select "Copy" from the menu of choices -- or you can print it directly by selecting "Print Picture".

Some members are having difficulty in understanding the problem so I have shown at the left the start of a solution. Note that ALL line segments have to be cut once and once only so you have to take your red line outside the diagram; your red line must not go through a junction; it must not cross itself; it can start and finish wherever you want it to, not necessarily as shown here and the two ends don't have to join up.

To see an answer, continue to scroll down.

Here is one possible answer. The secret is to first identify the areas bounded by an odd number of line segments. These are shown as red circles. Obviously, these must be the areas to start and finish. It is then a simple matter if finding a track to cut all the other line segments.

I had only one correct answer, which was from John Stafford. So there was no prize this month as we have to have a minimum of three correct entries to go in the draw.

[home] [back]