数学题：一块长方形铁皮，从四个脚各切掉一个边长为5厘米的正方形，然后做成盒子。（长方形的长为30厘米，宽为25厘米）这个盒子用了多少铁皮？它的容积有多大？（如下图）

数学题解答：

1.用的铁皮面积：30×25-5×5×4=650(平方厘米)

2.盒子的容积：（30-5-5）×（25-5-5）×5=1500（立方厘米）

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