Question

Write the smallest digit and the greatest possible digit in the blank space of each of the following numbers so that the number formed is divisible by 3.
= __ 6724

Answer 1

$6+7+2+4=19$

If we add 2 then the digit is divisible by $3(19+2=21).$

$2$ is the smallest digit

$26724=2+6+7+2+4=21.$

If we add 8 then the digit is divisible by $3(19+8=27)$

$8$ is the largest digit

$86724=8+6+7+2+4=27.$