No, you can not. But one must distinguish two cases:

1, the probability as "to happen", which is of course always independently 1/2.

2, the probability as "to have already happened" in the whole event.

I think we are talking about 2 here.

Just think of it in my verson of the Snow white puzzle. When she woke up, how likely it happened to January 1st? Very unlikely, wasn't it?

 

所有跟帖： 

• 明白您的意思，但那是醒來的概率，不是硬幣朝上的概率，不是嗎？ -露重煙微- ♀ (0 bytes) () 11/10/2023 postreply 14:14:00

• As part of the event they are no longer independent (case 2) -中間小謝- ♂ (110 bytes) () 11/10/2023 postreply 14:19:51

• 是的，這也是一個我當初很困惑的點，讓我一度轉成了1/2和1/3派。也就是像您列的，認為問題的問法有歧義。 -露重煙微- ♀ (0 bytes) () 11/10/2023 postreply 15:05:00

• 不過後來發現還是1/2，這裏我先買個關子，看還有沒有更多人想討論的。 -露重煙微- ♀ (0 bytes) () 11/10/2023 postreply 15:08:00