Question

Difference between the three digit number and the number formed by reversing its digit is always divisible by which number

Answer 1

Let A, B, and C be the digits of the original number from left to right. Then the actual number is 100A + 10B + C. The number obtained by reversing this is 100C + 10B + A. The difference between the two is 

| 100A+10B+C - (100C+10B+A) | = 
| 99A - 99C | = 
99 |A - C| 

So the number is always divisible by 99. 

Of course, this also means it's divisible by any factors of 99: 
1, 3, 9, 11, 33, 99

Hope this will help u.... :-)