Question

What is the missing digit which makes the number $128$_$2$ exactly divisible by $8$?

• A. $1$
• B. $2$
• C. $3$
• D. $4$

Answer 1

Answer: (C)

$3$

We know the divisibility rule for $8$:
If the last three digits are divisible by $8$ or last three digits of the given number are zeros, then the number is divisible by $8$.
Here $12832$ is divisible by $8$, because the last three digits is divisible by $8$.

So, option C is correct.