Question

Using divisibility tests, determine the given number $10,00,001$ is divisible by $11$.

Answer 1

We know that a number is divisible by $11$, if the difference between the sum of digits at odd places and the sum of digits at even places is either $0$ or multiple of $11$.

Here, Sum of digits at odd places $=1+0+0+1=2$

And Sum of digits at even places $=0+0+0=0$

Since, the difference $=2–0=2$.

Therefore, the given number is not divisible by $11$.