285.245 mins

來源: 於 2009-10-10 16:32:37 [博客] [舊帖] [給我悄悄話] 本文已被閱讀：次

Time =
(40/10)*50+(40/10)*10+(10*0.1*4+10*0.9*0.1*3+10*09*09*0.1*2+10*09*09*09*0.1)/10*50
= 285.245 mins

4 hours 45mins 14.7 seconds