.据说有人给酒肆的老板娘出了一个难题：此人明明知道店里只有两个舀酒的勺子，分别能舀7两和11两酒，却硬要老板娘卖给他2两酒。聪明的老板娘毫不含糊，用这两个勺子在酒缸里舀酒，并倒来倒去，居然量出了2两酒，聪明的你能做到吗？

-.酒肆is said to have been addressed to the wife out of a difficult problem: this person knows very well that the store only two of wine ladle spoon, ladle 7, respectively, to two and 11 two of wine, but insists his wife sold two liquor 2. Intelligent wife in no uncertain terms, use of these two years酒缸scoop spoon in wine, and inverted to倒去, actually basing revenue plans on spending the 2 two of wine, clever you can do it?