Question

If I add a 2 digit number and the number formed by reversing the digits, then the sum is surely divisible by

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• A. 2
• B. 23
• C. 11
• D. None of These

Answer 1

The correct option is C

11

Let a be the tens place digit and b be the units place digit, then the original number is 10 x a + 1 x b.The new number after reversing the digits is 10 x b + 1 x b. Therefore the sum will be:
(10a + b) + (10b + a) = 11a + 11b

= 11 (a + b)
Which is divisible by 11.