设乙的含盐量X 则甲是3x100*3x+300*x＝400*0.15600x=60x=0.1答：甲的含盐量是30% 第二题设乙的含盐量X 则甲是3x100x+300*3x＝400*0.151000x＝60x＝0.06答：甲的含盐量是18%
