Question

Fill in the blank with smallest digit to make $21.....84$ divisible by $8.$

Answer 1

Since as we know that last three digits of a number is divisible by $8$then number is divisible by$8.$

Last three digits of a number is $21.....84$ is $x84$ which is divisible by $8$ , where $x$ is the smallest digit.

when $x=1$ the last three digit of $21x84$ is $184$ which is also divisible by $8.$

Hence, the smallest digit to be placed in blank space is $1$ then digit $1$ to make $21.....84$ divisible by $8$.