"我们当初学了微积分，学了离散，学了线性". 来来用你们的牛刀试一试...

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How many ways are there to create a six digit number using digits 1 to 6 (without repetition) such that each pair of adjacent digits are relatively prime?

所有跟帖： 

• 人家又没说学数论了，这题咋会做？:)) -A-Momy- ♀ (0 bytes) () 04/12/2010 postreply 08:48:34

• 俺酸：学了有什么用，会做又怎么样？ 和：）～ -20146- ♀ (0 bytes) () 04/12/2010 postreply 08:51:04

• You may want to view it as a problem of 离散数学. -BeLe- ♀ (0 bytes) () 04/12/2010 postreply 08:54:43

• 欢迎数学家来坛子辅导 -Bin123- ♂ (0 bytes) () 04/12/2010 postreply 08:57:55

• 那学过离散的不就会做嘛。如果不会 -酱紫- ♀ (88 bytes) () 04/12/2010 postreply 09:02:14

• 这个是MC的题？那应该用初中生的知识就能做出来才对啊。 -gingertea- ♀ (12 bytes) () 04/12/2010 postreply 09:04:01

• i think so. my son did. -janeice65- ♀ (0 bytes) () 04/12/2010 postreply 13:59:23

• The answer is here, but you got to tell me where you got the pro -borisg- ♀ (189 bytes) () 04/12/2010 postreply 09:11:29

• 4X3!X3! ? -网恋无罪- ♂ (99 bytes) () 04/12/2010 postreply 09:19:39

• 3 and 6 should not be together. -BeLe- ♀ (0 bytes) () 04/12/2010 postreply 09:21:36

• 120? -A-Momy- ♀ (0 bytes) () 04/12/2010 postreply 09:25:03

• my answer was 72. -酱紫- ♀ (105 bytes) () 04/12/2010 postreply 09:30:59

• Need correction. forgot 3 and 6 not relative prime -网恋无罪- ♂ (0 bytes) () 04/12/2010 postreply 09:23:23

• 72 ? -网恋无罪- ♂ (393 bytes) () 04/12/2010 postreply 10:00:56

• 回复："我们当初学了微积分，学了离散，学了线性". 来来用你们的牛刀试一试... -MaoXin- ♂ (661 bytes) () 04/12/2010 postreply 09:45:29

• 大概这种就是国内以前所谓的练基本功吧 -酱紫- ♀ (205 bytes) () 04/12/2010 postreply 10:16:32

• 回复："我们当初学了微积分，学了离散，学了线性". 来来用你们的牛刀试一试... -calligraphy- ♂ (511 bytes) () 04/13/2010 postreply 10:23:44