Question

Ralph is 3 times as old as Sara. In 6 years, Ralph will be only twice as old as Sara will be then. Find Ralph's age now.

Which of the following equations could be used to solve the problem?

Answer 1

Let the present age of Ralph be x.
then Sara will surely be
`(x)/(3)`

Now,
After 6 years,

Ralph = x + 6
Sara =
`(x)/(3) + 6 = (x + 18)/(3)`

According to question,

Ralph after 6 years = 2*Sara after 6 years

`x + 6 = 2( (x + 18)/(3) ) \\ 3x + 18 = 2x + 36 \\ 3x - 2x = 36 - 18 \\ x = 18 \: years`

Ralph present age is 18 years and that of Sara is 6 years.