Question

the sum of a two digit number and reserve two digit number is a multiple of​

Answer 1

Answer:

Let the 2 -digit number be 10x + y

Reverses d=2 - digit number = 10y + x

Sum of this 2 number = 10x + y + 10y + x

                                      = 11(x+y)

The sum of a two digit number and reserve two digit number is a multiple of​  11.

Hope this helps you.

Answer 2

Answer:

In this case, the relevant number property to remember is that the sum of two two-digit numbers whose units and tens digits have been reversed is always a multiple of 11, and the difference of such numbers is always a multiple of 9.