For every tree you must mark a tent horizontally or vertically adjacent to it. No tent can be in an adjacent square to another tent (even diagonally) but a tree can border any number of tents. The numbers by each row and column tell you how many tents there should be in that row or column. Can you locate the tents?

This patchwork is in three colours - blue, purple and red. If we don’t want any same-coloured pieces to share a border, what colour will the pieces at a and b be?

Which two of these block piles could be fitted neatly together to make a perfect 3 x 3 x 3 cube?