解一道六年级奥数题,求过程

2025-06-28 14:23:42
推荐回答(1个)
回答1:

解:由1234组成四位数有4^4=256个。然后个百位与十千位相同的有1111,2112,1221,1331,3113,1441,4114,2332,3223,2442,4224,4334,3443,4444,2222,3333,1122,1133,1144,2211,2233,2244,3311,3322,3344,4411,4422,4433,1232,1342,1243,2134,2123,2321,2343,2431,3124,3234,3212,3421,3432,4213,4312,4323共44个。
所以有256-44=212个。