Puzzleup 2015 (15) Hands of a Clock - 拼圖

題目網址: http://www.puzzleup.com/2015/
http://www.puzzleup.com/2015/puzzle/?15
答題時限: 11月５日７ＰＭ－比賽結束（約12月16日）
加分時限: 11月５日７ＰＭ－11月11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）　　

◆HANDS OF A CLOCK

How many times at least two of the three hands (hour, minute, second) of a
clock exactly overlap between 10:30 and 22:30?

Note: All hands move in a continuous motion with no discrete jumps.

在早上十點半與晚上十點半之間，

鐘面上的時分秒三根針有至少兩根針完全重合的次數有多少？

注意: 三根針都以連續方式前進，沒有不連續的跳動。

--
'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

--