A Farmer has twelve sheep and decides to put each of them into a separate pen; but to make the pens he has only 12 long hurdles and 6 half length hurdles. How can he do it?
The farmer needs to arrange the 12 long hurdles in the shape of a hexagon made of 6 triangles, and then use the six short hurdles to divide each triangle into two.
Alan Butler spotted a solution which left a spare hurdle - can anyone improve on this?
Tim Bray spotted a solution which had 4 spare hurdles, although I suspect he might have cut the hurdles!!!!
Following my comments suggesting he may have cut some of the hurdles, Tim has come up with a couple of other solutions, which certainly don't need a saw.
This one uses 11 long and 6 short, leaving one spare long hurdle
This one uses 12 long and 4 short, leaving two spare hurdles.