用1.2.3.4这四个数字组成24个四位数
1,2,3,4。的4位数组合共有256组,具体如下;1111,1112,1113,1114,------ 2111,2112,2113,2114,------3111,3112,3113,3114,1121,1122,1123,1124,------2121,2122,2123,2124,-------3121,3122,3123,3124,1131,1132,1133,1134,------2131,2132,2133,2134,-------3131,3132,3133,3134,1141,1142,1143,1144,------2141,2142,2143,2144,-------...全部
1,2,3,4。的4位数组合共有256组,具体如下;1111,1112,1113,1114,------ 2111,2112,2113,2114,------3111,3112,3113,3114,1121,1122,1123,1124,------2121,2122,2123,2124,-------3121,3122,3123,3124,1131,1132,1133,1134,------2131,2132,2133,2134,-------3131,3132,3133,3134,1141,1142,1143,1144,------2141,2142,2143,2144,-------3141,3142,3143,3144,1211,1212,1213,1214,------2211,2212,2213,2214,------3211,3212,3213,3214,1221,1222,1223,1224,------2221,2222,2223,2224,------3221,3222,3223,3224,1231,1232,1233,1234,------2231,2232,2233,2234,------3231,3232,3233,3234,1241,1242,1243,1244,------2241,2242,2243,2244,------3241,3242,3243,3244,1311,1312,1313,1314,------2311,2312,2313,2314,------3311,3312,3313,3314,1321,1322,1323,1324,------2321,2322,2323,2324,------3321,3322,3323,33241331,1332,1333,1334,------2331,2332,2333,2334,------3331,3332,3333,3334,1341,1342,1343,1344,------2341,2342,2343,2344,------3341,3342,3343,3344,1411,1412,1413,1414,------2411,2412,2413,2414,------3411,3412,3413,3414,1421,1422,1423,1424,------2421,2422,2423,2424,------3421,3422,3423,3424,1431,1432,1433,1434,------2431,2432,2433,2434,------3431,3432,3433,3434,1441,1442,1443,1444,------2441,2442,2443,2444,------3441,3442,3443,3444,4111,4112,4113,4114,------4211,4212,4213,4214,------4311,4312,4313,4314,4121,4122,4123,4124,-----4221,4222,4223,4224,------4321,4322,4323,4324,4131,4132,4133,4134,-----4231,4232,4233,4234,------4331,4332,4333,4334,4141,4142,4143,4144,-----4241,4242,4243,4244,------4341,4342,4343,4344,4411,4412,4413,4414,4421,4422,4423,4424,4431,4432,4433,4434,4441,4442,4443,4444,最末一位是4的有:48组,可能性是48/256=0。
1875=18。75%。末2位都是4的有16组,可能性是16/256=0。0625=6。25%。收起