Question

Which of the following numbers is divisible by 11?
(a) 7138965
(b) 10000001
(c) 10834
(d) 901154

Answer 1

A number is divisible by 11 if the difference of the sums of alternating digits is divisible by 11.
Sum of the digits at odd places = 1 + 0 + 0 + 0 = 1
Sum of the digits at even places = 0 + 0 + 0 + 1 = 1
Required difference, 1 − 1 = 0
Since, 0 is divisible by 11.
Therefore, 10000001 is divisible by 11.
Hence, the correct answer is option (b).