Question

average age of 30 students is 13 yrs.When the age of the teacher is added to them,average becomes 14 . What is the age of the teacher​

Answer 1

Step-by-step explanation:

Given:-

Average age of 30 students is 13 yrs.When the age of the teacher is added to them,average becomes 14 .

To find:-

What is the age of the teacher ?

Solution:-

Average age of 30 students = 13 years

Number of students = 30

We know that

Average = Sum of all observations/Number of all observations

=>Sum of all observations / 30 = 13

=>Sum of all observations = 13×30

Sum of all observations = 390

Sum of the ages of 30 students = 390

If the teacher is added to the 30 students then

Number of all observations = 30+1 = 31

Number of total people = 31

Average age of 31 people = 14

Average = Sum of all observations/Number of all observations

=>Sum of all observations /31 = 14

=>Sum of all observations = 14×31

=>Sum of all observations = 434

Sum of the ages of 31 people = 434

Sum of the ages of 30 people = 390

Age of the teacher =

Sum of the ages of 31 people - Sum of the ages of 30 people

= 434-390

= 44years

Answer:-

The age of the teacher = 44 years

Used formula:-

• Average = Sum of all observations/Number of all observations