Tim has been very busy arranging teddies.
He sent us pictures of his arrangements. Well done Tim!
Tim said that he couldn't arrange the houses and teddies on the map
when there were six colours, but he wasn't sure why. In fact, this
is quite a famous problem. You can read about it on the NRICH site or at www.cut-the-knot.org , for example (our teddy
bear problem is equivalent to finding two orthogonal Latin
squares of order 6).