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Puzzle of the Day

These puzzles are also printed in Eight days a week, a booklet published by the Association of Teachers of Mathematics.

The numbers 1, 2 and 3 have been placed at the corners of a triangle. Arrange the numbers 4, 5, 6, 7, 8, and 9 on the sides, so that the numbers along each side (including the corners) add up to 17.

Answer: 1, 5, 9, 2, 4, 8, 3, 6, 7