Let the present age of Ralph be x.
then Sara will surely be [tex] \frac{x}{3} [/tex]
Now,
After 6 years,
Ralph = x + 6
Sara = [tex] \frac{x}{3} + 6 = \frac{x + 18}{3} [/tex]
According to question,
Ralph after 6 years = 2*Sara after 6 years
[tex]x + 6 = 2( \frac{x + 18}{3} ) \\ 3x + 18 = 2x + 36 \\ 3x - 2x = 36 - 18 \\ x = 18 \: years[/tex]
Ralph present age is 18 years and that of Sara is 6 years.
