Fill each box of the magic square, with a number such that the number adds up to 18 horizontally, vertically and diagonally? #[(, ,), (, ,), (, ,)]#

#[(7, ,), (, 6,), (, 10,)]#

1 Answer
Apr 17, 2016

#[[7, 2, 9], [8, 6, 4], [3, 10, 5]]#

Explanation:

We can fill in the unknown squares, one at a time to satisfy the constraints:

#[[7, ?, ?], [?, 6, ?], [?, 10, ?]] -> [[7, ?, ?], [?, 6, ?], [?, 10, 5]] -> [[7, ?, ?], [?, 6, ?], [3, 10, 5]]#

#-> [[7, ?, ?], [8, 6, ?], [3, 10, 5]] -> [[7, ?, ?], [8, 6, 4], [3, 10, 5]] -> [[7, 2, ?], [8, 6, 4], [3, 10, 5]]#

#-> [[7, 2, 9], [8, 6, 4], [3, 10, 5]]#

Bonus

An example #4xx4# magic square is:

#[[1, 12, 7, 14], [8, 13, 2, 11], [10, 3, 16, 5], [15, 6, 9, 4]]#

This one adds up to #34# in each column, row, diagonal or #2xx2# block of cells.