If
So, if the difference is 0, 11, 22, 33, ….
Then, Number is divisible by 11
Is 308 divisible by 11?
Sum of digits at odd Places = 8 + 3 = 11
Sum of digits at even Places = 0
Difference = 11 − 0 = 11
Since 11 is divisible by 11
∴ 308 is divisible by 11
Is 1331 divisible by 11?
Sum of digits at odd Places = 1 + 3 = 4
Sum of digits at even Places = 3 + 1 = 4
Difference = 4 − 4 = 0
Since difference is 0
∴ 1331 is divisible by 11
Is 61809 divisible by 11?
Sum of digits at odd Places = 9 + 8 + 6 = 23
Sum of digits at even Places = 0 + 1 = 1
Difference = 23 − 1 = 22
Since 22 is divisible by 11
∴ 61809 is divisible by 11
Is 5081 divisible by 11?
Sum of digits at odd Places = 1 + 0 = 1
Sum of digits at even Places = 8 + 5 = 13
Difference = 13 − 1 = 12
Since 12 is not divisible by 11
∴ 5081 is not divisible by 11