Answer/Step-by-step explanation:
All numbers that are divisible by 9 are also divisible by 3.
Since 3 goes into 9, if 9 is a factor, 3 is also a factor.
Example:
81 is divisible by 9.
So, 81 is also divisible by 3.
Another example:
1,273,050 is divisible by 9.
So 1,273,050 is also divisible by 3.
But the other way around is not necessarily true. If 3 goes into a number, 9 may or may not go into the number.
That is, if a number is divisible by 3, you cannot necessarily know that it is divisible by 9.
Example (seems like it works):
18 is divisible by 3. 18 is also divisible by 9.
But it doesn't work every single time so it cannot be a rule.
Example(sometimes it doesn't work):
24 is divisible by 3.
24 is not divisible by 9.