Question

what is the test of divisibility of 11

Answer 1

find the difference between the sum of digits of earth and some of places and even places of a number if the difference = 0 or multiple of 11 then the number is divisible by 11 example 623910

sum of digits on other places =0+2+3=5
sum of digits on even places =1+9+6=16
difference =16-5=11

hence ,639210 is divisible by 11

Answer 2

If the difference of sum of odd place digit and even place digit is divisible by 11 , then the whole number is divisible by 11.

For Example :-

121

Sum of odd place digit = 1+1 = 2

Sum of even place digit = 2

Their Difference is 0

0 is divisible by 11

So 121 is divisible by 11.