回複:first Q : 969 second Q:10626

回答: first Q : 969 second Q:10626jinjing2010-09-07 21:39:24

The answer to the second question should be C(19,4)+C(19,3)=C(20,4).

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I mean second Q; We can put 0 for 4 cases.So, the -jinjing- 給 jinjing 發送悄悄話 (19 bytes) () 09/08/2010 postreply 13:10:35

請您先登陸,再發跟帖!