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	Select the correct option:
A) 54.48 B) 54.68 C) 54.6 D) 54.58 E) 54.9
Explanation:   (55×50)+(60×55)+(45×60)/55+60+45   8750/160=54.68   Answer: 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