Question

divisibility rule of 9

Answer 1

sum of each digit of the number must be divisible by 9

Answer 2

divisiblity rule of 9 is that the
sum of all the digits of the number must be 9, if so then the no. is divisible by 9.

example:99
their sum 9+9=18
now again 1+8 =9
therefore the no. is divisible by 9

example:98
9+8=17
now again 1+7=8
hence their sum is not 9 therefore the no. 98 is not divisible by 9