Answer:
Step-by-step explanation: Let x represents Sara's age, since Ralph is 3 times as old, the Ralph's age will be 3x.
In 4 years time, Sara will be x+ 4 , Ralph will also be 3x + 4
It was said that Ralph will be as twice as Sara's age in 4 years
⇒ 3x + 4 = 2 ( x+4)
⇒ 3x + 4 = 2x + 8
collecting the like terms
3x - 2x = 8 - 4
x = 4
Since x represents Sara's age, then Sara is 4 years and since Ralph is presently 3 times Sara's age, then Ralph's age is 3 x 4 = 12 years