首页
登录
职称英语
There are 10 students in a classroom. If each student shakes hands with exactly
There are 10 students in a classroom. If each student shakes hands with exactly
游客
2024-01-12
73
管理
问题
There are 10 students in a classroom. If each student shakes hands with exactly 3 other students, what is the total number of handshakes?
选项
答案
15
解析
对于“握手问题”,可以从“握手的人”和“握手的行为”两个角度解题。
(1)方法一:从“握手的人”的角度看,每个同学都要跟其他3个不同的同学握手,即每个同学要握手3次。因为一共10个同学,所以一共需要握手3×10=30次;但每次握手时。都有2个同学参与,即A与B握手的同时B也与A握了一次手,因此每一次“真正握手”都被计算了2次,实际握手数量应为30/2=15次。
(2)方法二:从“握手的行为”的角度看,可以设想把10个同学组织起来同时握手。第一轮握手:将10个同学分成5组,每组的2个同学握手,共握手5次。第二轮握手:重新进行的分组,要求每个组的同学都不与上述5组的任意一组相同,每组的2个同学握手,共握手5次。第三轮握手:再重新进行的分组,要求每个组的同学都不与上述10组的任意一组相同,每组的2个同学握手,共握手5次。此时,所有的同学都恰好握手3次,共握手5+5+5=15次。
转载请注明原文地址:http://tihaiku.com/zcyy/3355299.html
相关试题推荐
Studentscanlearnmathematicsonlybyexploringitontheirown,withgenerous
Asbusinessgrowsmorecomplex,studentsmajoringinspecializedareaslikethos
Studentsinthemetropolitanschooldistrictlackmathskillstosuchalargede
Theschoolboardrulingmandatingthatphysicallyhandicappedstudentsbeplaced
Since1965therearefourtimesasmanyBlackcollegestudentsenrolled,andthe
Studiesofthepoliticalorientationsof1,055collegestudentsrevealedthatth
Onthetournamentrosterarelistedseveraltennisstudents,mostallofwhichp
ExactlywhenintheearlymoderneraNativeAmericansbeganexchanginganimalfu
ExactlywhenintheearlymoderneraNativeAmericansbeganexchanginganimalfu
ExactlywhenintheearlymoderneraNativeAmericansbeganexchanginganimalfu
随机试题
WhatchangeshappenedattheAcademyAwards?[br][originaltext]Thisyear,
Avoideggs.Drink8glassesofwateraday.Eatingcarbswill【C1】______.Nut
TheU.N.InternationalAtomicEnergyAgency______[originaltext]TheU.N.I
Fewpeopleexpectluxurywhileflying,butthesedays,【T1】________.It’snot
[originaltext]M:Excuseme.MayIhavesomeinformationaboutthereceptionpar
开口于舌下襞的腺体是()A.下颌下腺 B.舌下腺 C.腮腺 D.
强心苷治疗心力衰竭的主要适应证是A.严重贫血诱发的心力衰竭 B.由瓣膜病、高血
有关毒性反应的叙述,错误的是A.危害多较严重 B.包括慢性毒性反应和急性毒性反
房地产不仅在租赁、抵押、征收、分割、损害赔偿、税收、保险等活动需要估价,房地产估
施工成本计划的编制以成本预测为基础,关键是确定()。A.目标成本 B.预
最新回复
(
0
)