来源:学生作业帮 编辑:搜狗做题网作业帮 分类:英语作业 时间:2024/08/19 15:26:40
GRE数字大小比较题(详见补充)
The number of different duos that can be formed from a group of 5 people
The number of different trios that can be formed from a group of 5 people
这两个数答案给的是一样大?为什么?
肯定一样大啊
高三了没?这是排列组合的问题
C52 = C53