Some numbered cards were used to form numbers in a 3x3 grid. The sum of the numbers in all rows and columns should be the same, but isn't: the row totals are 34, 31 and 40, for example. Move only one card and make all totals the same!

[1][2]      [3]   [1][9]

[1][9]      [9]      [3]

   [9]   [1][9]   [1][2]

Take the nine at bottom left; turn it round so it becomes a 6, and put it on the nine at top right. All rows and columns will add up to 31.

Posted by K Sengupta on 2023-08-06 08:12:12