Rons age is two thirds of marks age. Marks age is three fifths of saras age. Sara is 9 years older than Ron. How old is mark
sara's age ---- 5x
Marks's = 3x
Rons age = (2/3)(3x) = 2x , notice how I avoided fractions?
5x - 2x = 9
x = 3
so Mark is 9, (Sara is 15, Ron is 6)