A school has `"20"` teachers,one of them retires at the age of `60`years and a new teacher replaces in this change reduces the average age of the staff'by `2` years,the age of new teacher is

The mean age of 25 teachers in a school is 40 years। A teacher retires at the age of 60 years and a new teacher is appointed in his place। If the mean age of the teachers in this school now is 39 years, then the age (in years) of the newly appointed teacher is_______ .

The mean ago of 25 teachers in a schools is 40 years. A teacher retires at the age of 60 years and a new teacher is appointed in his place . If now the mean age of the teachers in this schools is 39 years, then the age (in years) of the newly appointed teacher is

The mean ago of 25 teachers in a schools is 40 years. A teacher retires at the age of 60 years and a new teacher is appointed in his place . If now the mean age of the teachers in this schools is 39 years, then the age (in years) of the newly appointed teacher is

The average age of 24 boys and a teacher is 15. When the teacher's age is excluded the average decreases by 1 . What is the age of the teacher ?

Out of 10 teachers of a school, one teacher retires and in place of him a new teacher 25 years old joins. As a result of it average age of the teachers reduces by 3 years. Age of the retired teacher (in years) is: (a) 55 (b) 60 (c) 58 (d) 56