Answer:
80
Step-by-step explanation:
3 is for the staff members
20 is for the students
if there are 12 staff members
3/20=12/x ,then we multiply the numerator of the first fraction with the denominator of the second and vice versa.
3*x=20*12
3x=240
x=240/3
x=80, so there are 80 students and 12 staff members :)
