The average age of 30 students in a class is 12 years. The average age of a group of 5 of the students is 10 years and that of another group of 5 of them is 14 years. The average of the remaining students is:
Show answer & explanation
Correct answer: B
Explanation
The correct answer is Option 2 i.e. 12 years.
The average age of 30 students in a class = 12 years
The average age of a group of 5 of the students = 10 years
The average age of another group of 5 of them = 14 years
According to the question,
The average of the remaining students = (30 × 12 - 5 × 10 - 14 × 5)/20 = 240/20 = 12 years