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HMMT 二月 2000 · GEN 赛 · 第 17 题

HMMT February 2000 — GEN Round — Problem 17

专题
Discrete Math / 离散数学
难度
L3
来源
HMMT

题目详情

  1. In ho w man y distin t w a ys an the letters of ST ANTON b e arranged?
解析
  1. There are 7! w a ys to arrange those letters. Ho w ev er, for ev ery distin t arrangemen t, there are 2! 2! = 4 total arrangemen ts of the 2 T's and 2 N's. Therefore, the total 7! n um b er of distin t w a ys to arrange the letters is = 1260 . 2!2!