Question

The number 111, 111, 111, 111, is divisible by

• A. 9 and 11
• B. 5 and 11
• C. 3 and 9
• D. 3 and 11

Answer 1

The correct option is D 3 and 11

The number $111111111111$is divisible by 3 $\because 1+1+1+1+1+1+1+1+1+1+1+1=12$
$12$ is divisible by 3 so the number 111, 111, 111, 111, is divisible by 3
The number $111,111,111,111,$is divisible by 11 because the difference of the sums of alternating digits is 0