But first of all, you have to be very good to get extra points, and the points you get according to your grades are different, usually up to 20 points.
But every place and every school is different. The better the school, the more difficult it is. Your child is still very young. You can learn piano and violin, but there are more people to learn. But the classical guitar is unpopular, because few people play it, so it is easy to get high marks.