d****t
发帖数: 139 | 1 【 以下文字转载自 Mathematics 讨论区 】
发信人: doglet (妩), 信区: Mathematics
标 题: 两道初中数学题，求解
发信站: BBS 未名空间站 (Mon May 4 21:01:22 2009)
1. In a certain game, players throw 5 standard 6-sided dice at one time. On
a single throw of the 5 dice, what is the probability of rolling "
quadruples" (exactly four dice showing the same number)?
2. Two of the numbers -3, -5/4, -1/2, 0, 1, 1/3, 1, 4/5, and 2 are selected
randomly without replacement. What is the probability that the numbers
represent the slopes of two perp | c**********e
发帖数: 2007 | 2 Why ask here?
On
selected
【在 d****t 的大作中提到】
: 【 以下文字转载自 Mathematics 讨论区 】
: 发信人: doglet (妩), 信区: Mathematics
: 标 题: 两道初中数学题，求解
: 发信站: BBS 未名空间站 (Mon May 4 21:01:22 2009)
: 1. In a certain game, players throw 5 standard 6-sided dice at one time. On
: a single throw of the 5 dice, what is the probability of rolling "
: quadruples" (exactly four dice showing the same number)?
: 2. Two of the numbers -3, -5/4, -1/2, 0, 1, 1/3, 1, 4/5, and 2 are selected
: randomly without replacement. What is the probability that the numbers
: represent the slopes of two perp
| S******y
发帖数: 1123 | 3 1) 6 / (6*6*6*6*6)
2) Number of two perdendicular lines groups
divided by
2
C
9
Disclaimer: just my guess
time. On
selected
【在 d****t 的大作中提到】
: 【 以下文字转载自 Mathematics 讨论区 】
: 发信人: doglet (妩), 信区: Mathematics
: 标 题: 两道初中数学题，求解
: 发信站: BBS 未名空间站 (Mon May 4 21:01:22 2009)
: 1. In a certain game, players throw 5 standard 6-sided dice at one time. On
: a single throw of the 5 dice, what is the probability of rolling "
: quadruples" (exactly four dice showing the same number)?
: 2. Two of the numbers -3, -5/4, -1/2, 0, 1, 1/3, 1, 4/5, and 2 are selected
: randomly without replacement. What is the probability that the numbers
: represent the slopes of two perp
| s*****n
发帖数: 2174 | 4 I guess neither of your solutions is correct bah.
【在 S******y 的大作中提到】
: 1) 6 / (6*6*6*6*6)
: 2) Number of two perdendicular lines groups
:
: divided by
: 2
: C
: 9
: Disclaimer: just my guess
:
: time. On
| g*******y
发帖数: 380 | 5 第二题不感兴趣.
第一题:
所有可能的情况6*6*6*6*6
需要出现的情况可能是:1,1,1,1,(2/3/4/5/6);2,2,2,2,(1/3/4/5/6).....依此类推.
概率是(5*6)/(6*6*6*6*6) | s*****n
发帖数: 2174 | 6 不要忘了还有不同的排列呢.
分子是 6 x 5 x 5
分母是 6^5
【在 g*******y 的大作中提到】
: 第二题不感兴趣.
: 第一题:
: 所有可能的情况6*6*6*6*6
: 需要出现的情况可能是:1,1,1,1,(2/3/4/5/6);2,2,2,2,(1/3/4/5/6).....依此类推.
: 概率是(5*6)/(6*6*6*6*6)
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