As D97x7 says, girls tend to do better in exams.
This is partly because they are more motivated by approval from parents teachers, etc. and partly because they are more willing to apply themselves to stuff that they don't necessarily find inherently interesting.
Back when I was at school, boys tended to do better than girls in most subjects, but, as teaching methods have changed towards an obsession with tests and rote learning rather than with quality lesson content, the results have skewed in the other direction.