your age = 2011-birthyear
you assert:
birthyear + age =111
Some quick substitution to get birthyear and age
Mod(birthyear, 100) + (2011 - birthyear)
move around the compents
2011 + mod(birthyear,100) - birthyear
Pull out a negative:
2011 -(birthyear - mod(birthyear,100) )
results are either
2011 - (1900) = 111
2011 - 2000 = 11
2011 - 1800 = 211
woohoo math

edit on 18-1-2011 by catlantis because: added a 1




