Question

A three digit number $4x2$ is divisible by 9. Find the value of digit $x$.

Answer 1

Since, $4x2$ is divisible by $9$, then $4+x+2$ is divisible by $9$
i.e. $6+x$ is divisible by $9$
$6+x=9$ or $18$ or $27$.....
i.e. $x=9-6$ or $18-6$ or $27-6$ .....
$x=3$ or $12$ or $21$ ......
Since, $x$ is a digit, therefore $x=3$