首页
登录
职称英语
Ben and Ann are among 7 contestants from which 4 semifinalists are to be selecte
Ben and Ann are among 7 contestants from which 4 semifinalists are to be selecte
游客
2025-02-27
32
管理
问题
Ben and Ann are among 7 contestants from which 4 semifinalists are to be selected. Of the different possible selections, how many contain neither Ben nor Ann?
选项
A、5
B、6
C、7
D、14
E、21
答案
A
解析
The number of possible selections of 4 semifinalists that do not contain Ben or Ann is equal to the number of possible selections of 4 semifinalists from the remaining 7-2 = 5 contestants, which is equal to
. Alternatively, the number of possible selections of 4 semifinalists from the remaining 5 contestants is equal to the number of possible selections of exactly 1 non-semifinalist, which is equal to 5.
The correct answer is A.
转载请注明原文地址:https://tihaiku.com/zcyy/3974718.html
相关试题推荐
BenandAnnareamong7contestantsfromwhich4semifinalistsaretobeselecte
Oneintegerwillberandomlyselectedfromtheintegers11to60,inclusive.Wha
Twodifferentpositiveintegersxandyareselectedfromtheoddintegersthat
Ifanintegerisrandomlyselectedfromallpositive2-digitintegers,whatist
Ifanintegerisrandomlyselectedfromallpositive2-digitintegers,whatist
Atalentcontesthas8contestants.Judgesmustawardprizesforfirst,second,
Atalentcontesthas8contestants.Judgesmustawardprizesforfirst,second,
Supposexandyareselectedrandomlyfromtheset{1,2,3,4,5}andtheycan
Fourdifferentpersonswillbeselectedfrom2menand5womentoserveonacom
Fivepairsofsocksareofdifferentcolor.Iftwosocksaretobeselectedatr
随机试题
VisualPerspectivePerspectiveinartisthewaythatartistsrepresentthree-di
由于这些原因,在过去四十年间人们对这一课题进行了大量的理论研究工作。(havebeendone)Forthesereasonsagreatdeal
A. B. C. D.
结构化布线设计中,规定信息插座的安装位置的子系统是()。A.工作区子系统
某碳化深度测点的3次实测值分别为1.75mm、1.75mm和1.25mm,则该测
2021年4月,我国本外币贷款余额187.85万亿元,同比增长12%;人民币贷款
关于军休干部的需要,下列说法错误的是( )。A.具有鲜明的政治倾向性和特殊的荣
能力类型的差异是指( )上的差异A.天赋条件(如聪明、一般和迟钝) B.男女
心室肌细胞动作电位3期复极化A.因Na+内流而产生 B.因Ca2+内流而产生
社区获得性肺炎病原体排在首位的是A:金黄色葡萄球菌 B:肺炎克雷伯杆菌 C:
最新回复
(
0
)