Question

$4a9$ is divisible by 9 if the digit ${}^{\prime }{a}^{\prime }$is equal to:

• A. 5

Answer 1

The correct option is A 5

For the number to be divisible by 9 the sum of digits of number must be a multiple of 9.
Sum of the digits of $4a9=4+a+9=13+a$

$13+a$ should be a multiple of 9 to satisfy the condition. The nearest multiple of 9 next to 13 is 18.

Therefore, $13+a=18$

So, $a=18-13=5$