1. “You’ve got a lot of marbles,” said Sam. “But only reds, greens and blues. How many in all?” Alan smiled. “You can work it out, Dad,” he replied. “The blues are nine more than a third of the reds, the reds are a third of the total, and I’ve got twice as many blues as greens.” Well?

27 marbles in all

36 marbles in all

32 marbles in all