You can find your age with this trick :
1. Multiply the first number of your age by 5. (if your age is < 10, then the first number is 0; if your age is >99, example 115, then the first number is 11, the second number is 5).
2. Add 3 to the result.
3. Double the answer.
4. Add the second digit of the number to the answer.
5. Substract 6 from it.
The answer will be your age.. =D
Source : http://easycalculation.com/funny/tricks/age-calc.php