Question

If a and b are any digits from 1 to 9 to form a number ab, the ab+ba is always multiple of

Answer 1

Whenever we add 2 numbers ab and ba it will always be a multiple of 11
For example
12+21=33(multiple of 11)

Answer 2

Let me solve it without taking any numbers.

So we ve to add ab and ba
Let's first break this nos.

Ab = 10a +b ( a is in the tenth place)
Ba = 10b+a ( b is in the tenth place)
Now adding them,
Ab +ba = 10a+b +10b+a
= 11a+11b
=11(a + b)
Clearly sum of ab and ba Is a multiple of 11


Mark it as the brainy one!!