应该是高数题

来源：百度知道 编辑：UC知道 时间：2024/05/15 11:52:41
there were 210 matches on a soccer tournament. how many team took part on the tournament if each team played twice against each opponent?
permutation, please.

组合的问题：2*C(2,n)=210（2为上标,n下标）=》n(n-1)=210=》n=15
So there are 15 teams.Em...maybe...

有210场足球比赛。有多少球队参加了比赛上，如果每个队的比赛与每个对手的比两次？
设有x个队比赛，则总场数为x(x-1)=210,x=15(-14舍去)
有15个球队参加了比赛
fifteen