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The probability is 0.6 that an “unfair” coin will turn up tails on any given toss. If the coin is tossed 3 times, what is the probability that at least one of the tosses will turn up tails?
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当前版本由 AndyLiu 更新于2023-08-01 11:15:57 感谢由 AndyLiu 对此题目的解答所做出的贡献。
当前版本由 Helen 更新于2019-01-04 16:26:46 感谢由 Helen 对此题目的解答所做出的贡献。
3次全是正面的概率是P=(0.4)^3=0.064，那么至少有一次是反面的概率就是1-0.064=0.936
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是这样的，举个例子如果反一次有3种情况，正正反，正反正，反反正，就是相当于反一次的概率就要是C13*0.096=3*0.096，反两次和反三次也要这么算，最后结果是C13*0.096+C23*0.144+C33*0.216=0.936
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笔误，是正正反，正反正，反正正
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0.144和0.096分别要再乘3
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