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

Answer:-

Given:

Average age of Rajesh & Brijesh is 65 years.

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

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.

Answer 2

Answer:

29 yrs

the age of rajesh and brijesh can not be determined.

Step-by-step explanation:

1st method:

2 = 65 yrs

3 = 53 yrs,

clearly ,we can see that the average decreases when one person included.

decrease = 65-53 = 12 yrs

This 12 affects in both rajesh and brijesh age.

total effect = 12 ×2person = 24 yrs

then age of chetesh will be : 53 - 24 = 29 years

2nd method :

total age {R+B} = 65×2 = 130

total age {all three} = 53×3 = 159

difference = 159 - 130 = 29 yrs