Find all pandigital sums of the form
(with no zero) in ascending order of ghi and find a pattern in these sums.
Pattern aside, all pandigital sums must be evenly divisible by 9.
This is because x + y + z = 0 mod 9 if all digits 1-9 are represented in x, y and z exactly once.
But if x + y = z mod 9,
then x + y - z = 0 mod 9,
so 2z = 0 mod 9,
so z = 0 mod 9.
Edited on June 28, 2016, 8:11 pm