In a school with 50 students (Boys + Girls), the average weight of a boy and a girl is in the ratio of 3:2, and the total weight of boys and girls is the same. The number of teachers in the school is 20% less than the number of boys. The average weight of a teacher is 50 kg. If the total weight of the teachers is 25% more than the total weight of the boys, find the difference between the average weight of the boys and the average weight of the girls.