作业帮a math question in english,who can help me with this?A motel cleaner has 8 master keys at home to open all the rooms in a large motel.Each room can be opened by just one of these keys.If 40% of the rooms are leftunlocked,what is the probability that
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a math question in english,who can help me with this?A motel cleaner has 8 master keys at home to open all the rooms in a large motel.Each room can be opened by just one of these keys.If 40% of the rooms are leftunlocked,what is the probability that
a math question in english,who can help me with this?
A motel cleaner has 8 master keys at home to open all the rooms in a large motel.
Each room can be opened by just one of these keys.If 40% of the rooms are left
unlocked,what is the probability that the cleaner can get into a specific room if
he selects three keys at random before leaving home to go to work?
if posible,please answer in english and write down each step.
这是一个英文的数学问题
有个人他有八把钥匙,可以开所有房间的门.一天他要进去某一个房间.若果所有房间60%的门开了,他只带了其中三把钥匙(随机抽选),有多少概率可以开到那扇门?
a math question in english,who can help me with this?A motel cleaner has 8 master keys at home to open all the rooms in a large motel.Each room can be opened by just one of these keys.If 40% of the rooms are leftunlocked,what is the probability that
lz你确定这个是原题?
额..允许我质疑一下题目哈...我不太确定题目里提到的8把钥匙是不是均匀地能够打开剩下的六成的门 因为如果不是的话概率是会随着每把钥匙能打开的门所占剩下六成锁上的门的百分比的变化而变化.
如果是的话那就很简单了 概率就是0.4(开了的门)+0.6(没开的门)＊3/8(拿对钥匙的可能性)=.
ps.lz好像有点理解错题意了 1.If 40% of the rooms are left unlocked的意思是4成的门是打开的 2.what is the probability that the cleaner can get into a specific room if.意思是那个人能够"进入房间"的概率而不是能"打开门"的概率 因为门有可能是根本没有锁的
这是概率论里面的是非问题。
也就是说在8把钥匙里面取3把，用C8(3)表示
【C8(3)这是排列组合，因为这里输入不了，就将就点吧】
接着，
房间打开的概率是0.6
房间打不开的概率是0.4
那么可以打开门的概率就是C8(3)*（0.6）^3*(1-0.6)^5對不起,我不太懂排列組合..能否用通俗的算數解出來?...
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这是概率论里面的是非问题。
也就是说在8把钥匙里面取3把，用C8(3)表示
【C8(3)这是排列组合，因为这里输入不了，就将就点吧】
接着，
房间打开的概率是0.6
房间打不开的概率是0.4
那么可以打开门的概率就是C8(3)*（0.6）^3*(1-0.6)^5
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