甲;乙;丙所用时间之比是:3:4:5
甲;乙;丙效率之比是:1/3:1/4:1/5=20:15:12
甲:940*【20/(20+15+12)】=400
乙:940*【15/(20+15+12)】=300
丙:940*【12/(20+15+12)】=240
甲;乙;丙所用时间之比是:3:4:5
甲;乙;丙效率之比是:1/3:1/4:1/5=20:15:12
甲:940*【20/(20+15+12)】=400
乙:940*【15/(20+15+12)】=300
丙:940*【12/(20+15+12)】=240