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
2025-02-24
47
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:http://tihaiku.com/zcyy/3971340.html
相关试题推荐
Thedailyrateforahotelroomthatsleeps4peopleis$39foronepersonand
Inacertainroom,allexcept18ofthepeopleareover50yearsofage.If15o
Apositiveintegerwithexactlytwodifferentdivisorsgreaterthan1mustbeA、a
Amembershiplistof720peopleshowsthat36havefirstandlastnamesthatbeg
[img]2012q1/ct_egreqm_egreqtbz2_0258_20121[/img][br]Ofpeople20yearsofage
Asalespersonmadeaprofitof$50onthesaleofabicyclethatcostthesalesp
If55percentofthepeoplewhopurchaseacertainproductarefemale,whatist
Amanagerisforminga6-personteamtoworkonacertainproject.Fromthe11c
PERCENTOFTHE300PEOPLEINGROUP1ANDTHE400PEOPLE
[img]2015m7x/ct_egreqm_egreqtbz1_0073_20153[/img]Eachofthepeopleinthreegr
随机试题
Whyisthewomancalling?[br][originaltext]W:Hello.ThisisAnnaParkercall
某吸毒者的HIV抗体初筛阳性,确认实验出现一条gp160带,应如何处理( )。
宫颈淋病奈瑟茵感染,常伴有A.大肠埃希菌感染 B.支原体感染 C.立克次体感
具有活血调经、凉血安神功效的药物是()A.川芎 B.桃仁 C.丹参
某只股票要求的收益率为15%,收益率的标准差为25%,与市场投资组合收益率的相关
急性梗阻化脓性胆管炎的患者可见的是( )。A.腹痛,寒战高热,黄疸 B.进行
下列评价类型中更适合用于选拔人才的是()。A.诊断性评价 B.个体内差异评价
建筑信息模型(BIM)技术在施工图设计阶段的作用不包括()。A.建筑生态模
建设工程定额按编制程序和用途分类时,概算定额的编制对象是()A.独立的单项工程
某孕妇,25岁,生产一脊柱裂畸形儿,可能与哪种营养素缺乏有关?( )A.维生素
最新回复
(
0
)