Question

A school has four sections of chemistry in class XII having 40, 35, 45 and 42 students. The mean marks obtained in chemistry tests are 50, 60, 55 and 45 respectively for the four sections. The overall average of marks per students is:

• A. 53
• B. 45
• C. 55.3
• D. 52.25

Answer 1

The correct option is D 52.25

Total number of students $=40+35+45+42=162$
Total marks obtained
$=(40\times 50)+(35\times 60)+(45\times 55)+(42\times 45)$
$=8465$
Overall average of marks $=\frac{8465}{162}=52.25$