Question

Which of the following numbers is divisible by 11?

• A. 101
• B. 111
• C. 1111
• D. 11111

Answer 1

The correct option is C 1111

According to the divisibility test of 11, if the difference between the sum of digits at odd places and the sum of digits at even places is either zero or divisible by 11, then the given number is divisible by 11.

Option a: 101
The sum of digits at odd places = (1 + 1) = 2
The sum of digits at even places = 0
Their difference 2 - 0 = 2, which is neither zero nor divisible by 11

Option b: 111
The sum of digits at odd places (1 + 1) = 2
The sum of digits at even places = 1
Their difference = 2 - 1 = 1, which is neither zero nor divisible by 11

Option c: 1111
The sum of digits at odd places = (1 + 1) = 2
The sum of digits at even places = (1 + 1) = 2
Their difference = 2 - 2 = 0, which follows the divisibility test of 11.
So, 1111 is divisible by 11.

Option d: 11111
The sum of digits at odd places = (1 + 1 + 1) = 3
The sum of digits at even places = (1 + 1) = 2
Their difference = 3 - 2 = 1, which is neither zero nor divisible by 11

So, option ‘c’ is correct.