A school has 4 section of Chemistry in Class X having 55, 35, 45 and 42 students. The mean marks obtained in Chemistry test are 50, 60, 55 and 45 respectively for the 4 sections. Determine the overall average of marks per student.
Choose the correct choice from the following answers.
A) 50.15
B) 52.06
C) 51.25
D) 53.06
E) none of the above

Rationale: "required average marks = 55 ã — 50 + 35 ã — 60 + 45 ã — 55 + 42 ã — 45 / 55 + 35 + 45 + 42 = 2750 + 2100 + 2475 + 1890 / 162 = 9215 â  „ 177 = 52.06 answer b"
Answer: B