If the ratio of boys to girls is 11:9 and there are 124 more boys than girls:
Let's say that the number of boys is 11x and the number of girls is 9x.
So, 11x = 9x + 124
2x = 124
x = 62
The total number of students = Number of boys + number of girls
= 11x + 9x
= 20x
= 1240 students
Thus, the total number of students attending the school is 1240.