Question

In the following replace * by the smallest number so that the given number is divisible by the number mentioned:
$85*63$ by $9$.

Answer 1

Divisibility rule of $9$- A number is divisible by $9$ it the sum of its digits is divisible by $9$.

Sum $=8+5+6+3=22$

If we add $5$ to $22$ we will get $5+22=27$ which is divisible by $9$.

Therefore, $5$ is the smallest number that can replace $*$ in the given number making it divisible by $9$.