Question

The average age of child ina clas 35 is 11.the average age including teacher is 12.How old is the teacher​

Answer 1

In context to questions asked,

We have to determine the age of teacher.

As per questions,

We have

The average age of child in a clas 35 is 11.

So sum of ages of all child will be,

$35 \times 11 = 385$

The average age including teacher is 12.

Sum of ages of all child's and teacher will be,

$12 \times 36 = 432$

So, for determining the age of teacher we will subtract the total age of all 35 students from the total age of 35 students and teacher.

Thus we will get,

$432 - 385 = 47 \: year$

Hence age of teacher will be 47 years