首页
登录
职称英语
Each person at a party shook hands exactly once with each of the other people at
Each person at a party shook hands exactly once with each of the other people at
游客
2024-01-12
26
管理
问题
Each person at a party shook hands exactly once with each of the other people at the party. There was a total of 21 handshakes exchanged at the party.
Column A Column B
The number of people at the party 8
选项
A、if the quantity in Column A is greater
B、if the quantity in Column B is greater
C、if the two quantity are equal
D、if the relationship cannot be determined from the information given
答案
B
解析
参加某次舞会中的每个人都与其他的所有与会者刚好握一次手。在这个舞会中共有21次握手。
解:本题的正确答案为(B)。设出席舞会的人数为n,则握手的总次数=n!/[2! (n-1)!]=n(n-1)/2=21 so, n2-n-42=0。解二次方程可得,n=-6或n=7,舍去负根得出席这次舞会的人数为7。
转载请注明原文地址:https://tihaiku.com/zcyy/3356778.html
相关试题推荐
OnJuly20,1969,NeilArmstrongbecamethefirstpersontowalkonthe
OnJuly20,1969,NeilArmstrongbecamethefirstpersontowalkonthe
OnJuly20,1969,NeilArmstrongbecamethefirstpersontowalkonthe
OnJuly20,1969,NeilArmstrongbecamethefirstpersontowalkonthe
_________workhasbeendonetoimprovepeople’slivingstandard.A、ManyB、Agreat
Bythetimethewar_________,mostofthepeoplehadalreadyleft.A、brokeoutB、
Oursocietyhaschangedand____________init.A、sothepeoplehaveB、thepeopleh
Theseplasticflowerslookso___________thatmanypeoplethinktheyarereal.A、b
Weallknowthatitispossibleforordinarypeopletomaketheirhomeso
Weallknowthatitispossibleforordinarypeopletomaketheirhomeso
随机试题
RenownedChinesedirectorZhangYimou’slatestfilm,RidingAloneforThous
[originaltext]Predictingthejobsorskillsthatwillbeindemandyearsfro
企业()系统,是企业文化在意识形态领域中的再现。A.30 B.45 C.6
设A是3阶矩阵,P=(a1,a2,a3)是3阶可逆矩阵,且P-1AP=
有实验证明肩关节固定1周所致的挛缩需52天才能治愈,固定3周,治愈大约所需的天数
世界上最著名的围海造田的国家是荷兰。()
引起感觉需要的最小刺激量称为阈限。()
下列瞳孔的变化对诊断小脑幕切迹疝有意义的是A.患侧瞳孔先缩小,再散大 B.患侧
小柴胡汤与蒿芩清胆汤中均含有的药物是A:陈皮,甘草B:枳壳,大枣C:半夏,甘
上尿路结石大多数为A、草酸钙结石 B、磷酸镁铵结石 C、磷酸钙结石 D、尿
最新回复
(
0
)