Q. The average age of 30 students is 15 years. If the teacher’s age is also included then the average age increases by 1 year. The age of the teacher is
✅ Correct Answer: (B)
46 years
Explanation: According to question ,
The average age of 30 students = 15 years
Total age of 30 students = 30 × 15 = 450 years
Total age of 30 students and teacher = ( 15 + 1 ) × 31 = 496 years
∴ Age of teacher = Total age of 30 students and teacher - Total age of 30 students
Age of teacher = ( 496 – 450 ) = 46 years
Explanation by: Madan
According to question ,
The average age of 30 students = 15 years
Total age of 30 students = 30 × 15 = 450 years
Total age of 30 students and teacher = ( 15 + 1 ) × 31 = 496 years
∴ Age of teacher = Total age of 30 students and teacher - Total age of 30 students
Age of teacher = ( 496 – 450 ) = 46 years
The average age of 30 students = 15 years
Total age of 30 students = 30 × 15 = 450 years
Total age of 30 students and teacher = ( 15 + 1 ) × 31 = 496 years
∴ Age of teacher = Total age of 30 students and teacher - Total age of 30 students
Age of teacher = ( 496 – 450 ) = 46 years