标题: Check the confirmed JJ 8-24 [打印本页] 作者: cook 时间: 2002-9-11 15:08 标题: Check the confirmed JJ 8-24
116：Q 题目说下面那一个不可能是多边形的对角线个数
A 5 B 6 C 9 D14 E21？
要注意一个单词：polygon 是多边形
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Does anybody know how to calcuate the number of diagonals of polygon? thanks!
112.Q: 8苹果6个好的取4个至少1个坏的概率,
A::55.【确定】
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My answer: 1-C6,4/C8,4=11/14 =78.6% . Is that correct?
102、Q:how many square feet of carpeting that will be need to cover the floor that 14 feet long
(1) perimeter 52
(2) the greatest distance of 2*根号 85
A: D【确定】
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How do you know it is regular shape? E or uncomplete issue.
A: A【确定】
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My answer: C for example: (15,3.75) or (16,2.72) will get different answers.
86. Q 8人选2人，A去，B不去的概率。
A: 6/C(8，3)【确定】
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6/C(8,2)
7。Q:There are 8 books, 6 of them are paperbooks and 2 of them are hardbooks. What is the combination of at least one hardbook?
A: 40【确认】
R: C(2,1)*C(6,3)=40
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I think the question isn't clear? please advise!
5。Q:Is integer n a square of integer?
1)4n is a square of integer
2)n^3 is a square of integer
A: C【确认】
R:for 1,n maybe 1/4,insufficient;
for 2,n maybe 根号3,so insufficient
1+2,N must be integer,so C
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D, since n is integer
Thank!作者: tongxun 时间: 2002-9-11 17:14
116\ Cn,2 -n 这是对角线的运算公式, N 代表N边形.
112\ 55 是能取的种类,不是概率.
102\ 题目应该说明了是长方形.
89\ 肯定是C, 因为不管你的书是多少价钱,都需要运费. 16+2.75 与 15+3 是不一样的.
86\ C6,1/C(8，3)
7\ 题目肯定不完整! 因为没说取几本书. 记得原题为取两本书.
C2,1 * C6,1 +C2,2
5\ D I am sure.作者: cook 时间: 2002-9-11 17:29 标题: once more
first, thank you for advise but you confused that my answer is under the confirmed keys which is published on 全部确认过答案的本周数学 (2002-8-25), I just want to clarify and make sure.
116\ Cn,2 -n 这是对角线的运算公式, N 代表N边形. thanks!
112\ 55 是能取的种类,不是概率.
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Not for the question. anyway, we are agreed.
102\ 题目应该说明了是长方形. --Ok
89\ 肯定是C, 因为不管你的书是多少价钱,都需要运费. 16+2.75 与 15+3 是不一样的.
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You agree with me.
86\ C6,1/C(8，3)
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Can you explain why C(8,3) instead of C(8,2)
7\ 题目肯定不完整! 因为没说取几本书. 记得原题为取两本书.
C2,1 * C6,1 +C2,2
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Yeah, I think so
5\ D I am sure.
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you bet.作者: tongxun 时间: 2002-9-11 17:34
cook: because I am not in my home now, so I cannot caculate some questions you asked. I will replay these questions tonight.
Sorry!作者: tongxun 时间: 2002-9-11 20:48
