+----+----+----+----+----+ 1
+----+----+----+----+ 1-1/5
+----+----+----+--- 1-1/4
+----+----+----+----+----+- 1-1/5+1/4
| 30吨 |
甲:
30÷[(1-1/5+1/4)-(1-1/4)]
=30÷(1/2-1/5)
=100
乙:100X(1-1/5)=80
+----+----+----+----+----+ 1
+----+----+----+----+ 1-1/5
+----+----+----+--- 1-1/4
+----+----+----+----+----+- 1-1/5+1/4
| 30吨 |
甲:
30÷[(1-1/5+1/4)-(1-1/4)]
=30÷(1/2-1/5)
=100
乙:100X(1-1/5)=80