Question

The average of Rajesh's and Brijesh's age is 65 years. The average of Rajesh, Brijesh and Chetesh's age is 53
years. Find Chetesh's age​

Answer 1

Given:

Average age of Rajesh & Brijesh is 65 years.

Average age of Rajesh , Brijesh & Chetesh is 53 years.

Find:

Chetesh's age​

Solution:

Let,

Age of Rajesh be x ; Brijesh be y and Chetesh be z years.

We know that,

Average = sum of observations/Number of observations

Hence,

→ (x + y + z) / 3 = 53 years

→ x + y + z = 53*3

→ x + y + z = 159 -- equation (1)

Similarly,

→ (x + y) / 2 = 65

→ x + y = 65*2

→ x + y = 130 -- equation (2)

Subtract equation (2) from (1).

→ x + y + z - (x + y) = 159 - 130

→ x + y + z - x - y = 29

→ z = 29 years

Therefore, Chetesh's age is 29 years.

I hope it will help you.

Regards.

Answer 2

☆ Given:

• The average of Rajesh's and Brijesh's age is 65 years.
• The average of Rajesh, Brijesh and Chetesh's age is 53 years.

☆ To Find:-

• Chetesh's age

☆ Solution:-

We know that,

$\boxed {\boxed{ \sf{Average = \frac{Sum \: of \: observation}{Number \: of \: observations} }}}$

Step-by-step explanation:

Let Chetesh's age be z , Rajesh's age be x and Brijesh's age be y.

According the question,

$\implies \: \dfrac{x + y + z}{3} = 53$

$\implies \: x + y + z = 53 \times 3$

by multiplying 53 and 3

$\implies \: x + y + z = 159 \:..... \tt{equation \: 1}$

Now,

$\implies \: \dfrac{x + y}{2} = 65$

$\implies \: x + y = 65 \times 2$

by multiplying 65 and 2

$\implies \: x + y = 130 \: ......... \tt{equation \: 2}$

By subtracting equation 2 from equation 1,we got

$\implies \: x + y + z - (x + y) = 159 - 130$

$\implies \:z = 159 - 130$

$\tt{ \implies \: z = 29}$

$\tt{ \therefore \: Chetesh's age \: is \: 29 \: years}$

☆ Required Answer:

• Chetesh's age is 29 years.