The average age of a class of 34 students and a teacher reduces by 0.5 years,…
2026
The average age of a class of 34 students and a teacher reduces by 0.5 years, if the teacher is excluded. The initial average of the class including teacher is 16 years. Find the age of the teacher.
- A.
30 years
- B.
33 years
- C.
35 years
- D.
37 years
Attempted by 14 students.
Show answer & explanation
Correct answer: B
First, calculate the total age of the class including the teacher. There are 34 students + 1 teacher = 35 people.
With an average age of 16 years, the total sum is 35 × 16 = 560 years. Next, find the average age when the teacher is excluded.
The average reduces by 0.5 years, so it becomes 16 - 0.5 = 15.5 years. The total age of the 34 students is then 34 × 15.5 = 527 years.
Finally, subtract the students' total age from the initial total to find the teacher's age: 560 - 527 = 33 years.