Question 113
Let $k$ be a positive integer. Prove that there is a positive integer $N$ with the following properties:
a. $N$ has $k$ digits, none of which is $0$.
b. No matter how the digits of $N$ are rearranged, the resulting number is not divisible by $13$.
a. $N$ has $k$ digits, none of which is $0$.
b. No matter how the digits of $N$ are rearranged, the resulting number is not divisible by $13$.