Question

A mother's age is a square of her daughter's age. After 5 years, mother will be three times as old as her daughter. What is the present age of the mother? Please do it in simple method.

Answer 1

let the age of her daughter be x,
then the age of mother is x^2

After 5 years the age of mother = (x^2 + 5)
and the age of her daughter = (x + 5)

Then, according to question

=> x^2 + 5 = 3(x + 5)
=> x^2 + 5 = 3x + 15
=> x^2 - 3x - 10 = 0

=> x^2 + 2x - 5x - 10 = 0
=> x(x + 2) -5(x + 2) = 0
=> (x - 5) (x + 2) = 0

=> x = 5 or x = -2

But, age cannot be in negative

So, her daughter's age is 5 years old.

and the mother's age is (5)^2 = 25 years old.