Question

Question 21

In the given question, fill in the blanks to make the statement true.

The sum of a two-digit number and the number obtained by reversing the digits is always divisible by ___.

Answer 1

11
Let ab be any two-digit number, then the number obtained by reversing its digits is be.
Now, ab + ba = (10a + b) + (10b + a)
= 11a + 11b
= 11(a + b)
Hence, ab + ba is always divisible by 11 and (a + b).