设批了西红柿X千克,则豆角批了40-X千克
则
1.2X+1.6(40-X)=60
64-0.4X=60
0.4X=4
X=10
能赚:
10(1.8-1.2)+(40-10)(2.5-1.6)
=6+27
=33(元)