Question

If a sister is three times older than her brother .Five years earlier she was five times as old as her brother. What is the present age of the sister??

Answer 1

x=3y
x-5=5(y-5)
let x ND y are the current age of boy ND girl respectively....
now alive both eq ND find the value of x ND y
I think that it will help you

Answer 2

Let the present age of brother = x years
Given that the present age of sister is three times the age of her brother.
Therefore the present age of sister = 3x years

Five years ago
age of the brother = x - 5 years
age of sister = 3x - 5 years

Given that five years, earlier the age of sister is five times of brother
Therefore
3x - 5 = 5(x - 5)
3x - 5 = 5x - 25
2x = 20
x = 10 years

The present age of sister = 3x = 3*10 = 30 years


Hope this helps you.