单选题 LEAGUE RESULTS
Team Ntimber of
Games Won
A
B
C
D
E
X		 4
7
9
2
2
According to the incomplete table above．If each of the 6 teams in the league played each of the other teams exactly twice and there were no ties．How many games did team X win?(Only 2 teams play in a game．)
A. 4 B. 5 C. 6
D. 7 E. 10

【正确答案】 C
【答案解析】根据左侧不完整的表格，若联盟中6支队伍中的每一支都与其他的各支队伍比赛2次，并且没有乎局(tie)，X赢得了多少场比赛?
(每个比赛只有2支队伍参加)
由每支队伍都与另一队伍比赛了2次，且每次必有且仅有1支队伍获胜，可得总的获胜次数为：
[*]
上表中前5项的和为：4+7+9+2+2=24
30-24=6，所以X胜了6场。