Respuesta :
Answer:
11 if the average was 4 years ago.
Explanation:
4 years ago would be the average from 4 years later the total age 4 years ago.
Answer:
the avg age = 15 years
total stds= 9 years
total age 4 yrs age = 15-4
=11
total age= sum of the age of all the students
=11×9(the total students)
=99
; the total age 4 years ago was 99...
i am a maths dropout... I might not be right :(