If you were born in 1990, then you'll turn 22 on your birthday in 2012.
You would be born in 1969.
Given that the year you're looking at is 2010, if you were 20, you would be born in 1990.
On your birthday in 2012, you would turn 15.
You would have been born in 1990.
You would be 27 this year.
In 2012, you would have been born in 1990 if you have had your birthday this year. 1989 if you are 22 and haven't had a birthday yet this year.
1990
1990
1990
The year of birth would have been 1990.
You would be born in 1969.
If you were born in 1990, then you will turn 23 on your brithday in 2013.
Given that the year you're looking at is 2010, if you were 20, you would be born in 1990.
On your birthday in 2012, you would turn 15.
You would have been born in 1990.
You would be 27 this year.
17-year-olds in 2012 were born in 1995.