Puzzleup 2014 (20) Balls - 拼圖

作答時間已經全部結束，目前正在整理答案當中。請靜待結果出爐！

題目網址: http://www.puzzleup.com/2014/
http://www.puzzleup.com/2014/puzzle/?261

答題時限: 12月11日７ＰＭ－比賽結束
加分時限: 12月11日７ＰＭ－12月17日６：５９ＰＭ

答對可得基本分１００分。答案可上傳５次，每改１次答案從基本分扣２０分。　
比賽期間內可隨時上傳答案，加分時限內答對第ｎ天加（６－ｎ）分　 　　 　　
另依題目的難易有額外加分（如有８０％的人這題答錯，答對者加８０分）　　

◆Balls

There are six red balls and four black balls in a box. The balls are randomly
drawn one by one and the colors are tallied. The process is continued until
all the balls have been drawn. What is the probability that the number of red
balls is always bigger then the number of black balls throughout the whole
tallying process?

Enter your answer as a simplified fraction. Example:12/23

箱子裡有六個紅球跟四個黑球。

這些球隨機地逐一抽出並統計顏色，直到所有球都被抽出來為止。

試問在統計過程中紅球數目一直都大於黑球數目的機率是多少？

答案以最簡分數輸入，如 12/23。

--
'You've sort of made up for it tonight,' said Harry. 'Getting the
sword. Finishing the Horcrux. Saving my life.'
'That makes me sound a lot cooler then I was,' Ron mumbled.
'Stuff like that always sounds cooler then it really was,' said
Harry. 'I've been trying to tell you that for years.'
-- Harry Potter and the Deathly Hollows, P.308

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