1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33等任意6个数自相加尾数之和为23,一共有多少组合
问题描述：
1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33
等任意6个数自相加尾数之和为23,一共有多少组合
答
123456=21,12345=15,第五个数字为8 1234581234=10,第五六个数字和为13,即58和67 123458,123467123567=24>23,所以必须有4,134567=26>23,所以必须有2,234567=27>23,所以必须有1,共2种尾数组合123458,4*4*4*3*3*3=21612...