If the average marks of three batches of 55, 60 and 45 students respectively is 50, 55, 60, then the average marks of all the students is:

1. 53.33
2. 54.68
3. 55
4. None of these

Explanation

• 55 students get average marks of 55%.
• so 55*50=2750
• similarly, 60*55=3300
• & 60*45=2700
• now total no of marks obtain by all students of three batches= 2750+3300+2700=8750/=
• Total no of students= 55+60+45=160.
• By dividing total marks on each student , we get average marks obtain by each student
• so 8750/160 = 54.68