Question

If the average marks of three batches of $55,60$ and $45$ students respectively is $50,55$ and $60$, then what are the average marks of all the students?

• A. $43.5879$
• B. $65.7824$
• C. $54.6875$
• D. $34.2278$

Answer 1

Answer: (C)

$54.6875$

Total marks of first batch $=55\times 50=2750$
Total marks of second batch $=60\times 55=3300$
Total marks of third batch $=45\times 60=2700$
Total number of students in three batch $=55+60+45=160$
$\therefore$ Average marks of all the students $=\frac{2750+3300+2700}{160}=\frac{8750}{160}=54.6875$