The average age of a father and a mother is 35 years. The average age of the father, the mother and their daughter is 25 years. What is the age of their daughter?
Answer & explanation
Correct answer: option 4
Formula used = Total sum of all observation / Total number of observation
Average age of a father and a mother is 35 years
Sum of age of Mother and Father ( F + M ) = 35 × 2 = 70 years ----(1)
Average age of the father, the mother and their daughter is 25 years
Sum of age of the father, the mother and their daughter ( F + M + D ) = 25 × 3 = 75 years ---(2)
By putting sum of age of Mother and Father from Equation 1 in Equation 2 ,
( 70+ D ) = 75
D = 5 years
So , Age of Daughter is 5 years
The correct answer is Option (4) → 5 years