Answer:
80
Step-by-step explanation:
Initial ratio:
Teachers to students
1 : 15
Ratio after:
Teachers to students
3 : 40
The number of students did not change, so we can make the students of the initial ratio and the students of the ratio after the same.
1 : 15 = 8 : 120
3 : 40 = 9 : 120
120 units = 1200
1 unit =
Initial teachers = 8 units =