Joe has a set of 25 cards, one side red and one side green. He
has written one of the numbers 1 to 5 on each side of each card
such that no two cards are identical. He asked Penny to arrange
the cards in a 5-by-5 square, so that, red side up or green side
up (after turning cards over one at a time), she produced a very
special Latin Square in which not only were numbers not
duplicated in any row, column or diagonal, but also where two
cards touched corner to corner. The positions of some of the
numbers in Penny's solution are shown above. What are the
numbers hidden under L A T I N? WIN £15 will be awarded to the
sender of the first correct answer opened on Wednesday 5
December. The Editor's decision is final. Please send entries to
Enigma 1722, New Scientist, Lacon House, 84 Theobald's Road,
London WC1X 8NS, or to Answer to 1716 Pyramid selling: 3
tetrahedrons; 50 per cent increase The winner Steve Collins of
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