Rubil and Dev were preparing to have a water balloon fight. "No Fair" cried Rubil, "You have 3 times as many as I do!" Dev said "Fine!" and gave Rubil 10 more balloons. "Still not fair!" argued Rubil, "You still have twice as many as I do." How many mo
Dev must give Rubil another 20 water balloons, giving them each 60. Rubil started with 30 water balloons and Dev with 90.