Question

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:

• A. $53.33$
• B. $54.68$
• C. $55$
• D. None of these

Answer 1

Answer: (B)

$54.68$

Required average $=\left(\frac{55\times 50+60\times 55+45\times 60}{55+60+45}\right)$
$=\left(\frac{2750+3300+2700}{160}\right)$
$=\frac{8750}{160}$
$=54.58$