Question

The age of a father is equal to sum of the ages of his 6 children. After 15 years, twice we
age of the father will the sum of ages of his children. Find the age of the father.
Ans.60 years.​

Answer 1

father's age = x years

sum of age of children is y years

After 15 years,

Father's age = (x + 15) years

Sum of children's age = y + (15×6)

Sum of children's age = (y + 90) years

after 15 years,

2 (x + 15) = (y + 90)

2x + 30 = y + 90

2x-y=90-30

2x - x = 60

x = 60

y = 60