The least number to be added to the numbers to make them divisible by 9 is equal to the difference of the least multiple of 9 greater than the sum of the digits and sum of the digits.Sum of digits = 15.Nearest multiple of 9 greater than sum of digits = 18.Hence 3 has to be added.
Let the greater and the smaller number be g and s respectively.gs = 2560g + s exceeds g - s by 64 i.e., g + s - (g - s) = 64i.e., 2s = 64 => s = 32.g = 2560/s = 80.
EXAMIANS