Question

3. If the mean age of 30 students of a class is 10 years. If the age of their
teacher is also included than the mean is increased by 1 year. What is
the age of the teacher?​

Answer 1

let teacher age be x years

300+x = 341

x = 41 years

Answer 2

Step-by-step explanation:

40

The average age of 30 students is 9.

So the total age of 30 students is 30*9=270.

If the teacher includes the average age becomes 10.

Means the average age of 31 person is 10.

So the total age of 31 person is 31*10=310

Now the age of teacher is 310–270=40yr.