Answer:
2 3/4 hours
Step-by-step explanation:
We see from the figure that 2 students spent 1/4 hours and 3 students spent 3/4 hours.
So the total time spent is
2* (1/4) + 3(3/4) hours
= 1/2 + 9/4
=(2+9)/4 taking l.c.m
= 11/4
= 2 3/4 hours
The total time spent by 5 students on 1/4 hours and 3/4 hours is 2 and 3/4 hours.