What is the minimum number of strokes to reproduce the drawing below without lifting up the pencil from the paper (no tricks at all), and without passing over a line segment (or part of it) already drawn? You may begin and end wherever you like, and line segments may cross each other, but only as intersections.

Note: a new stroke occurs when a line type ceased because you have to stop and change direction.

(In reply to re(9): No Subject by pcbouhid)

Sorry Paulo.  I agree with Percy and Charlie.  The solution requires 15 strokes of the pencil.  Each stroke starts from a point.  The stroke BC in Percy's solution begins at point B and ends at point C.  14 additional strokes are required to complete the drawing.

Posted by Mindy Rodriguez on 2005-11-25 13:27:36