设甲成本x元.
(1+30%)x*90%+【(1+20%)*(2000-x)】*90%-2000=277
1.17x+【2400-1.2x】*0.9=2277
1.17x-1.08x=2277-2160
x=1300
乙成本:2000-1300=700元
设甲成本x元.
(1+30%)x*90%+【(1+20%)*(2000-x)】*90%-2000=277
1.17x+【2400-1.2x】*0.9=2277
1.17x-1.08x=2277-2160
x=1300
乙成本:2000-1300=700元