甲盒比乙盒多57颗棋子,从甲取出12颗放入乙后
甲比乙多 57 - 12*2 = 33颗.
甲现有 = (57 - 12*2) ÷ (1 - 4/7) = 77 颗
乙现有 = 77 × 4/7 = 44 颗
甲原有 = 77 + 12 = ⑧9
乙原有 = 44 - 12 = 32