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- 精华
- 0
- 积分
- 1300
- 经验
- 1300 点
- 威望
- 10 点
- 金钱
- 1907 ￥
- 魅力
- 783
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PREP 排列组合题, 请教
| Tanya prepared 4 different letters to be sent to 4 different addresses. for each letter , she prepared an envelope with its correct address. if the 4 letters are to be put into the 4 envelopes at random, what is the probability that only 1 letter will be put into the envelope with its correct address?(I/3) |
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