GUESS YOUR FRIEND'S BIRTH DATE

DO YOU KNOW that you can get your friend's birth date - month and year, just by doing these simple math calculating?
here...

1). ask them to use a calculator, and to type their birth date
2). ask them to multiply it by 4
3). add 13 to the result
4). multiply the result by 25
5). subtract 200 from the result
6) ask them to add their birth month
7). multiply the answer by 2
8). subtract 40 from the result
9). multiply it again by 50
10). ask them to plus the result by the last two digits number of their birth year.
then you take the calculator, then subtract 10500 from the result, what do you get?
your friend's birth date, month and year!

ALL THE BEST FOR YOU!!!