Question

What least number should be replaced for $\ast$ so that the number $67301\ast 2$ is exactly divisible by $9$?

Answer 1

A number is divisible by $9$ if the sum of its digits is divisible by $9$.

Now, Sum of the digits in given number $=6+7+3+0+1+2=19$, which is not divisible by $9$.

But, if we add $8$ to this sum, it becomes $19+8=27$, which is divisible by $9$

So, $6730182$ is divisible by $9$

So, the least number is $8$ which should replace for $\ast$ in the given number.