The rule for deciding if a number is divisible by 3 is to add up the digits of the number. If that total is a multiple of 3, the original number is as well. This applies to numbers of any length.
9 is greater than 6 and divisible by 3.
No. No number can be divisible by a number greater than it. 812 is greater than 6 so 6 cannot be divisible by 812.
80 is divisible by 5 and 4 and is greater than 75
304
304
If the sum of its' digits are divisible by 3 for all numbers greater than 9.
No. To be divisible by a number it must be greater than, or equal to, that number. 10 is less than 66, so 10 cannot be divisible by 66.
The answer is nothing
80
1002
It is 72
201