The Sum of a two digit number and the number obtained by reversing the order of its digits is 121.

The number given to us is in the form of ‘yx’,

Where y represents the ten's place of the number and x represents the units place of the number

Now, the given number is 10y + x

Number obtained by reversing the digits of the number is 10x+ y

It is given to us that the sum of these two numbers is 121 So, (10y + x) + (10x + y) = 121

10y + y + x + 10x = 121

11y + 11x = 121

11(y + x) = 121

x + y = 121/11 = 11

x + y = 11