Question

In a class, the average age of 30 students is 9 years. If the age of their teacher is included, it becomes 10 years. The age of the teacher (in years)is

Answer 1

Solution:-

given by:-

》average age of 30 stundent is 9 years

》let teacher age = x years

》total age 30×9 = 270

》inclueded teacher = 30×10= 270+x

》 = x = 300-270

》( teacher age = x = 30 years)

Answer 2

(9*30+x)÷31=10
270-x=310
x=310-270
x=40