Question

The average age of a mother and her three children is 10years. If the age of the children are 1, 4 and 7 years. How old is the mother with explanation​

Answer 1

No. Of people = 4

Average = 10

Age of children = 1, 4 and 7

Let the mother's age be x

x + 1 + 4 + 7/ 4 = 10

=> x + 12/4 = 10

=> x + 12 = 10*4

=> x + 12 = 40

=> x = 40 - 12

=> x = 28

Therefore, the age of their mother is 28.

Answer 2

Answer :-

The age of the mother is 28 years.

Explanation :-

Given :

• Average age of mother and three children - 10 years.
• Age of three children - 1, 4 and 7 years.

To find :

• The age of mother

Solution :

Let the age of mother be 'x'

According to question,

$\sf\longrightarrow \dfrac{1 + 4 + 7 + x}{4} = 10$

$\sf\longrightarrow \dfrac{12 + x}{4} = 10$

$\sf\longrightarrow 12 + x = 40$

$\sf\longrightarrow x = 40 - 12$

$\sf\therefore x = 28$

Hence, the age of mother is 28 years.

Additional information :-

• Average = Sum of quantities/No. of quantities
• For eg:- The average of 2, 3 and 4 will be 3. [2 + 3 + 4/3 => 9/3 = 3]