Question

The mean age of 30 students is 9 years. If the age of their teacher is included, mean becomes 10 years. Find the teacher’s age

do not use algebra​

Answer 1

Answer:

9.7 Years

Step-by-step explanation:

Mean Age of 30 students =9

mean Age of including teacher=10

Let X be the age of teacher:

Age of single student when mean is 30=

9/30=0.3 years

now for teachers age

0.3+X=10

X=10-0.3

X=9.7 years

Answer 2

Step-by-step explanation:

students age = 9

number of students = 30

let the teacher mean become = 10

THE teacher age = 10-30+9=29