An Inverted Magic Square
Using the digits 0, 1, 6, 8 and 9, fill a 5x5 grid with 2-digit numbers
(leading zeros are allowed, and necessary), such that:
- Each 2-digit number is unique,
- Each row, column and major diagonal has the same sum
(forming a magic square),
- When inverted (rotated 180 degrees), the resulting grid of numbers
also forms a magic square.
Source: Based on a problem from
The Little Giant Encyclopedia of Puzzles.
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