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? |
6 years 4 years 10 years 5 years |
5 years |
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 |