[問題]GWD25-11

由 **magic** » 2006-11-03 01:02

Q11
Of the three-digit positive integers that have no digits equal
to zero, how many have two digits that are equal to each
other and the remaining digit different from the other two?
A. 24
B. 36
C. 72
D. 144
E. 216
答案是E
請問這題該怎麼算阿
毫無頭緒@@

由 **Kyo** » 2006-11-03 02:51

前兩位數相同，後兩位數相同與頭尾兩位數相同各72個，總數就是216囉。

由 **magic** » 2006-11-08 17:22

感謝
了解了

[問題]GWD25-11

[問題]GWD25-11

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