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Name: Claudio
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You have 3 square napkins (one square foot each). What's the area of the largest square table you can cover with the 3 napkins? Please, give me the way to solve it, not only the solution. Thank you. :-)

I don't know of any "methods" for solving puzzles like this. I had to have 3 "Aha!"s (sudden insights) before I came up with a configuration for the napkins that will cover the largest square table. Try this: how would you arrange the napkins (imagine sewing their edges together where they meet) so they cover the largest ROUND table. (I just love symmetry.) I propose that the same configuration will cover the largest square table. The answer I get for the DIAGONAL of the table is:

1 + ( sqrt(2) ) / 2 [the form of the answer is, in itself, a hint]

For more information about puzzles like this and how to solve them, read

"Aha! Insight" by Martin Gardner, Scientific American, Inc., 1978


Correction: the diagonal is just 3/2, and if you write it as 1 + 1/2, then the form of the answer is, indeed, a big hint.


John Hawley

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