Question

The average age of 32 students is 10 years. If the teachers age is also included, the average age increases by one year. What is the age of the teacher?

Answer 1

given
average age of 32 students is 10years
total age =32×10 =320years
if teacher age is included then average be 11years
total age including teacher =11×33 =363years
teachers age =363-320
=43years
hope you got it.

Answer 2

Given :

The average age of 32 students is 10 years.  If the teachers age is also included, the average age increases by one year

To Find :

What is the age of the teacher?

Solution:

$Average = \frac{\text{Sum of all observations}}{\text{no. of observations}}$

The average age of 32 students is 10 years.

So, $10 = \frac{\text{Sum of age of 32 students}}{32}\\320 =\text{Sum of age of 32 students}$

Let x be the age of teacher

New sum = 320+x

New mean = 10+1=11 years

So,$11=\frac{320+x}{33}\\11 \times 33= 320+x\\363-320=x\\43=x$

Hence The age of teacher is 43 years