The average age of the 50 students of section A is 14 years, and the average age of the 30 students of section B is 6 years. What is the average age of the students of both sections taken together?
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → 11 years
The combined average is the total age of both sections divided by the total number of students.
Total age in section A \(=50\times14=700\) years
Total age in section B \(=30\times6=180\) years
\(\displaystyle \text{Average}=\frac{700+180}{80}=\frac{880}{80}=11\) years
The average age of both sections together is 11 years. The plain average of 14 and 6, that is 10, would be right only if the two sections had the same number of students.