Now A has 2m kg of pure alcohol, and B has 3m kg of pure water. Take A kg from A and pour it into B, and take A kg from B to A. At this time, A’s pure water is more than B’s alcohol by how many kg.
现有甲2m千克纯酒精，乙3m千克纯水，从甲取A千克倒入乙，从乙取A千克到甲，这时甲的纯净水比乙的酒精多多少千克．
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