Question

The number 4a6 is divisible by 3. Find the least value of a.

• A. 2
• B. 7
• C. 4

Answer 1

The correct option is A 2

For a number to be divisible by 3, the sum of all the digits of the number should be divisible by 3.
The number given is 4a6.

$\Rightarrow$ Sum of digits = 4 + $a$ + 6
= 10 + $a$

If $a=0$
$\Rightarrow$ Sum of digits = 10 + 0 = 10.

If $a=1$
$\Rightarrow$ Sum of digits = 10 + 1 = 11.

If $a=2$
$\Rightarrow$ Sum of digits = 10 + 2 = 12.
12 is divisible by 3.

Therefore, the least value of a is 2.