Number Theory
# Divisibility

Is 12345 divisible by 5?

**Note:** 12345 is divisible by 5 if it can be divided into groups of 5 with nothing left over.

Is 234 divisible By 9?

**repunit**. How many digits long is the smallest repunit that is divisible by 9?

For how many different values of $A$ is the three digit number $3A6$ even?

Note: $A$ can be any of the 10 digits from 0 to 9.