Question

Take a two-digit number ab. Then reverse the digits. If the difference between ab and the new number is cd, then cd is always divisible by.

• A. 9
• B. 11
• C. 10

Answer 1

The correct option is A 9

We are taking a 2 digit number ab. The difference between the original number and the number formed after reversing the digits is cd.

$\therefore$ cd = (10a + b) - (10b + a) = 9(a - b)

As cd is a multiple of 9, it is always divisible by 9.