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.
Let x be the current age of Sara. With this, Ralph's current age is 3x. In six years, Sara's and Ralph's ages would be x + 6 and 3x + 6, respectively. The equation that best represent the situation is,
3x+6 = 2(x + 6)
The value of x is 6. Therefore, Ralph's current age is 18 years old.