Question

$24x$ is a three-digit number. Find all the possible values of $x$ so that it is divisible by $3$.

Answer 1

The divisibility test for $3$ is that if the sum of the digits of a number is divisible by $3$ then the number itself will be divisible by $3$.

For $24x$ to be divisible by $3$,

$2+4+x=6+x$ must be divisible by $3$.

Hence, for this the values of $x$ are $0,3,6,9$.