A typist types four envelopes and four letters. She places the letters in the envelopes at random. What are the chances that onl

admin2016-01-14  34

问题 A typist types four envelopes and four letters. She places the letters in the envelopes at random. What are the chances that only three letters are in their correct envelopes?

选项

答案zero

解析 (如果三个都装对了,那么第四个也一定装对了,所以没有这种几率。)
转载请注明原文地址:https://kaotiyun.com/show/GvAK777K
0

相关试题推荐
最新回复(0)