Question

______Solve Q.78_______

Answer 1

10a+b+10b+a
=11a+11b
which is always divisible by 11

Answer 2

The two digit number must be of the form 10 x + y.

Every two digit number are in this form .

For example :

65 = 6 × 10 + 5

79 = 7 × 10 + 9

16 = 1 × 10 + 6

If we reverse the digits then the number becomes 10 y + x

For examples :

65 = 6 × 10 + 5

65 ===> 56

56 = 5 × 10 + 6

Thus this will be 10 y + x

Given :

The sum of the original and reversed digit is to be found .

10 x + y + 10 y + x

= > 11 x + 11 y

= > 11 ( x + y )

x + y is an integer .

Hence 11 divides x + y

ANSWER :

OPTION C

Hope it helps :-)

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