Question

A number in which each digit except 0 appears exactly 3 times is divisible by 3. for​ example, 777,555,222 and​ 414,143,313 are divisible by 3. explain why this is true

Answer 1

The sum of digits of such a number is a multiple of 3. According to the divisiblity rule for 3, that is all that is required for a number to be divisible by 3.