In 2015 a person was 15 years old and in 2010 the same person was 20 years old in which year was he born?

The information provided contains an inconsistency, as a person cannot be both 15 years old in 2015 and 20 years old in 2010. If the person was 15 in 2015, they would have been born in 2000. Conversely, if they were 20 in 2010, they would have been born in 1990. Therefore, the ages stated do not align correctly.