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- How to Prove the divisibility rule for $3$ 17 answers
I am trying to prove that $k$ is divisible by $3$ iff the sum of the digits of $k$ is divisible by 3 for all $k \in Z$.
I am not even sure what tags to use because I am not sure of right methods to use to solve this problem. I don't see how you could solve this with induction. Any tips on the general approach would be appreciated.