Some problems in life have neat, tidy answers that reward the search. Others yield only answers that continue to question.

Here are selections of puzzles that will challenge, bemuse and infuriate, perhaps all at the same time.

The answers will be posted a month after the puzzle first appears, but of course looking at the answers only brings relief until the next puzzle appears. Some require lateral thinking, thinking “out of the box”, and that is what Kinghorn Associates is all about.

Send your suggested answers to Kinghorn Associates, and we will publish the best.