Answer:
total ribbon collected is 147.5 meters.
Explanation:
Total students = 50
3/5 are girls
girls = 3/5*50 = 30
boys= 50-30 = 20
length of ribbon brought by girls = 30*2.75 = 82.5
length of ribbon brought by boys = 20*3.25 = 65
total length of ribbon = 82.5+65 = 147.5 metres