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标题: pp-ps-2-89 (機率高分難題) [打印本页]

作者: Kath1985 时间: 2010-4-21 22:36
标题: pp-ps-2-89 (機率高分難題)

89.9835-!-item-!-187;#058&007168

For one toss of a certain coin, the probability that the outcome is heads is 0.6.If this coin is tossed 5 times, which of the following is the probability that the outcome will be heads at least 4 times?

(A) (0.6)^5

(B) 2(0.6)^4

(C) 3(0.6)^4(0.4)

(D) 4(0.6)^4(0.4) + (0.6)^5

(E) 5(0.6)^4(0.4) + (0.6)^5

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【答案】E

硬幣的正反面機率都是0.5呀怎麼會是0.6
沒有人討論這個難題看不懂PP 想請教詳細解釋

作者: summer虾 时间: 2010-4-21 22:41
不能用常识来做数学==这样可能是因为硬币质量不均造成的，按照他给的条件做就好~（刚刚做CR，还没缓过来）

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