Q. 36

# Which of the following numbers is divisible by 11?

A. 1011011

B. 1111111

C. 22222222

D. 3333333

Answer :

Take the alternating sum of the digits in the number, read from left to right. If that is divisible by 11, so is the original number.

A. 1011011

Sum = 1 – 0 + 1 – 1 + 1 – 1 + 1 = 2

Since, 2 is not divisible by 11, 1011011 is not divisible by 11.

B. 1111111

Sum = 1 – 1 + 1 – 1 + 1 – 1 + 1 = 1

Since, 2 is not divisible by 11, 1011011 is not divisible by 11.

C. 22222222

Sum = 2 – 2 + 2 - 2 + 2 – 2 + 2 - 2 = 0

Since, 0 is divisible by 11, 22222222 is divisible by 11.

D. 3333333

Sum = 3 – 3 + 3 – 3 + 3 – 3 + 3 = 3

Since, 3 is not divisible by 11, 3333333 is not divisible by 11.

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