Question

109. If the digits of a two-digit number are in-
terchanged then the sum of the new number and
the original number is always divisible by
a) 9
b) 11
d) 33
c) 3
2.​

Answer 1

Answer:

b) 11

Step-by-step explanation:

Let the two digit number be XY.

After interchanging the number become YX.

YX + XY is always divisible by 11.

For example:

23+32=55/11

45+54=99/11

35+53=88/11