Information

The multiples grid

The multiples grid

Would you be able to place numbers 1 through 9 on a 3 × 3 grid so that the sum of the immediate neighboring numbers (including diagonals) is a multiple of that number?

Solution

Unless it is rotating the numbers, there is only one solution. The best way to start is with the central number, which should be a factor of 45, the sum of the 9 numbers.