设乙X吨,甲X+12.5吨,丙X+X+12.5-25=2X-12.5吨
X+X+12.5+2X-12.5=130
4X=130
X=32.5
甲=32.5+12.5=45吨
乙=32.5吨
丙=130-32.5-45=52.5吨