Question:
A number is divisible by 11, if the differences between the sum of digits at its odd places and that of digits at the even places is either 0 or
divisible by ————-.
Solution:
11
By test of divisibility by 1,1, we know that, a number is divisible by 11, if the sum of digits at odd places and even places are equal or differ by a
number, which is divisible by 11.