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  Choices:	A) 54.48	B) 54.68	C) 54.6	D) 54.58	E) None of these
Explanation:   (55×50)+(60×55)+(45×60) / 55+60+45   8750 / 160=54.68   Option 54.68
<result>B</result>
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