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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.

Draw a triangle and write a number between 1 and 9 at each corner. Now put the other six numbers in pairs on the sides. Is it possible to arrange them so that each line of four numbers adds up to 20?

Answer: 5 2 49 7 3 1 6 8 or 5 9 4 2 7 3 8 6 1