This diagram started life as a magic square containing the
consecutive series 1 to 16. All four rows, four columns and the two
long diagonals each summed to a constant total.
But then two numbers were swopped over, and then another two,
destroying the symmetry of the square.
The problem here is to (a) determine the original constant and
(b) decide which two pairs of numbers must be swopped back again to
restore the magic property of the diagram.
Find the solution online>>
