SOLUTION: in the year 2012 i was as old as the last two digits of my birth year. how old was i in 2012?

The trick is to use the fact that the last two digits of any year 
in the last century is found by sutracting 1900 from it.  For 
example the last two digits of the year 1975 was 1975-1900 which 
is 75.

                 age in 2012 = 2012-birthyear

last two digits of birthyear = birthyear-1900 

           So 2012-birthyear = birthyear-1900

                       Let b = birthyear

                   2012 - b  = b - 1900

                         -2b = -3912

                           b = 1956

So I was born in 1956, and I am 56 years old, because
the year 1956 was 56 years before 2012.

Edwin