Question: Jamie collects glass balls. He had 16 red balls and two times more blue balls. Later on, he lost 6 of the red balls, so he decided to buy some yellow balls to fill up his collection. How many yellow balls did he buy if, after all, he had 74 balls in total? Think carefully first, then make a decision:
Jamie had two times more blue balls than red ones, so he had 2 blue / red * 16 red balls = 32 blue balls. He lost 6 red balls so he had only 16 red balls - 6 red balls = 10 red balls. In total he had 32 blue balls + 10 red balls = 42 red and blue balls. He bought 74 balls - 42 red and blue balls = 32 yellow balls. So the answer is 32.