一道gre数学 Bottle A contains 7 liters of a mixture that is 12 p

一道gre数学 Bottle A contains 7 liters of a mixture that is 12 percent water by volume...
Bottle A contains 7 liters of a mixture that is 12 percent water by volume. Bottle B contains 8.5 liters of a mixture that is 10 percent water by volume. 比较volumeA 和 volumeB哪个大。。。。。我为什么觉得比不出来 答案是B大