作业帮 > 数学 > 作业

设集合P={1,2,3,4,5,6,7,8,9,10},P的子集A={a1,a2,a3},其中a1

来源:学生作业帮 编辑:作业帮 分类:数学作业 时间:2024/05/17 01:31:38
设集合P={1,2,3,4,5,6,7,8,9,10},P的子集A={a1,a2,a3},其中a1
取a1 = 1,则a2至少为4,则a3 = 7
a2 = 5,a3 = 8
a2 = 6,a3 = 9
a2 = 7,a3 = 10
同样的取a1 = 2,则a2 = 5,a3 = 8
a2 = 6,a3 = 9
a2 = 7,a3 = 10
取a1 = 3,a2 = 6,a3 = 9
a2 = 7,a3 = 10
取a1 = 4,a2 = 7,a3 = 10
所以好子集的个数为10个