If the average marks of three batches of 55, 60 and 45 students respectively is 50, 55, 60, what is the average marks of all the students? Choose the correct choice from the following answers:	A) 53.23	B) 54.68	C) 51.33	D) 50	E) 52
Explanation:   Average marks of batch 1 = 50   Students in batch 1 = 55   Total marks of batch 1 = 55 × 50   Average marks of batch2 = 55   Students in batch2 = 60   Total marks of batch2 = 60 × 55   Average marks of batch3 = 60   Students in batch3 = 45   Total marks of batch3 = 45 × 60   Total students = 55 + 60 + 45= 
<gadget id="calculator">55 + 60 + 45</gadget>
<output>160</output>
160   Average marks of all the students=(55×50)+(60×55)+(45×60)/160   =275+330+270/16   =875/16=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, what is the average marks of all the students?