If the average marks of three batches of 55, 60, and 45 students respectively is 50, 55, and 60 then the average marks of all the students is?
Note
Average marks of all students = (55×50+60×15+45×60)/160
= {(55×5)+(6×15)+(45×6)}/16
= (275+90+270)/16
= (635/16)
= 39.68