Enigmas & puzzles

Holy petunias
May 3, 2009

"Father Abbot?"

"Yes, Brother Uthelfrith?"

"Tomorrow at sunrise we perform the Rite of the Holy Flowerpots, in memory of Saint Sythelthwyth the Unpronounceable."

"That is correct, Brother."

"I have consulted The Book of the Divine Garden. This year's sacred bloom is the petunia and the holy colours are pink and purple. I have found the flowers and cleaned the 25 marble slabs that form the Sacred Square of Saints in the garden."

"Well done, Brother."

"My pardon, Father, but there are two things the book does not prescribe."

The abbot nodded. "The number of pots to be arranged and their disposition. No, those depend on the will of the Almighty and are revealed to those who are worthy. I can tell you that you must place three pots of pink petunias and five pots of purple ones. No more than one pot can go on any stone. And no pink petunia pot may be in line with any purple petunia pot, either vertically, horizontally, or diagonally."

"Father, I do not understand. How must I place the flowerpots?"

"Open your mind, Brother, and the answer will come."

How should the pots be arranged?



Prospect invites you to solve the puzzle and send us the solution. Correct answers will be entered into a draw. The winner will receive Before Sudoku: The World of Magic Squares (Oxford University Press, £7.99). Send your solution to? answer@prospect-magazine.co.uk by 15th May.

The winner will be announced in our May issue. Last month's winner was James Gomez, London SE5

Last month's answer

Herbert served first.

Nine games were played, so the first player to serve served five games and the other player served four. Suppose that the first player won x of the games he served, and y of the games he didn't serve. Then the total number of games that went against serve can be written as 5-x+y. But we also know that five games went against serve, which means that 5-x+y = 5 and therefore x = y. So the first player won 2x games—that is, an even number of games, and only Herbert did.