Question

Find the smallest positive number that can be multiplied with $666,$ to make it divisible by $4.$

Answer 1

For $666,$, the last two digits are $66,$ which is not divisible by $4.$
Hence, $1$ cannot be the answer.

Also, $666$ is divisible by $6.$
$\Rightarrow 666=111\times 2\times 3$
Here, $2$ is the only even factor.
$\therefore$ For divisibility by $4,$ we need another even factor.
The smallest positive even factor is $2.$

Hence, if $2$ is multiplied with the given number, it will be divisible by $4.$

$\frac{666\times 2}{4}=\frac{111\times 2\times 2\times 3}{4}=333$