一道比较头疼的数学题

题目

一道比较头疼的数学题
100个大盒子摆在桌子上.一些盒子被选中并且每个盒子里面被放入8个更小的盒子.然后这些更小的盒子中的一些被选中,并往每个里面放入8个更更小的盒子.同样的过程持续了几分钟.到了最后一共有233个空盒子.
请问这个过程中一共用了多少盒子?
题目的英文原文
One hundred large boxes are placed on the table.Some of these boxes are selected and into each of them 8 smaller boxes are placed.Then some of these smaller boxes are selected and into each of them 8 smaller boxes are placed.This process is repeated a few times.At the end of this process there are 233 empty boxes altogether.
How many boxes are there in total?

答案

每次放入小盒子 空的盒子就增加8－1个
（233－100）÷（8－1）＝19次
8×19＝152个