From Aert Kuipers
Andy Biddulph points out that there are many possible solutions to your fill-in-the-grid puzzle (9 February, p 25). He forgets that simplicity is a criterion for preferring one rule to another. Had the rule been as complex as he makes it, I would have turned to the next page without delay.
Biddulph explains that many brain-teasers test only whether you can spot the arbitrary choice made by the person devising the problem.
Surely this is what intelligence is for?
Oostkapelle, The Netherlands
