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
53
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
Weweremade(work)______allnight.towork
[originaltext]W:CanIhelpyou?M:Yes,[20]I’dliketoreadsomearticlesthat
PASSAGETHREE[br]Whatistheauthor’spurposeofmentioningvariousobservatio
Whatwillthemoneyfromfinesbeusedtodo?A、Tobenefitthelocalpeople.B、To
Youbecomesodeeplyabsorbedinanactivitythatyoulose_____oftime.A、trace
下列软件中,()都是系统软件。A.Windows98,Excel和Word
A. B. C. D.
(2017年真题)下列属于技术改造项目可行性研究的阶段的有()。A.确定投资方
公安机关在办理刑事案件中,必须重证据,重视犯罪嫌疑人的口供。( )
下列责任保险合同中,采用期内索赔制保险单对保险人和被保险人双方更有利的是(
最新回复
(
0
)