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acceleration (夜半蹄声到客船) 于 (Mon Jul 9 23:24:14 2007) 提到:
You throw a fair coin until you get 21 heads in a row.
What's the probability you will see 13 consecutive tails in the sequence
prior to stopping?
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jediknight (jk) 于 (Tue Jul 10 03:31:26 2007) 提到:
1-(1-(1/2)^13)^21
