A才料的成本是:
5元 x 4000 + (7700 - 7000 x 7%)÷ (4000 + 3000)x 4000
= 20000 + (7700 - 490)÷ 7000 x 4000
=20000 + 7210 ÷ 7000 x4000
=20000 + 4120
=24120
A才料的成本是:
5元 x 4000 + (7700 - 7000 x 7%)÷ (4000 + 3000)x 4000
= 20000 + (7700 - 490)÷ 7000 x 4000
=20000 + 7210 ÷ 7000 x4000
=20000 + 4120
=24120