Q11 of 46 Page 175

A father’s age is four times that of his son. After 5 years, it will be three times that of his son. How many more years will take if father’s age is to be twice that of his son?

Let, son’s age = x


Father’s age = 4x


According to problem,


⇒ 4x + 5 = 3(x + 5)


⇒ 4x + 5 = 3x + 15


⇒ x = 10


∴ son’s age = x = 10 years


∴ Father’s age = 4x = 40 years


Let, it will take y more years to be the father’s age twice than the son.


According to problem,


⇒ 4x + 5 + y = 2(x + 5 + y)


⇒ 45 + y = 30 + 2y


⇒ y = 15


∴ 15 more years will take if father’s age is to be twice that of his son.


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