[DSE 2019] 你地溫 數學 又溫成點呢？ [3]

話說就快又1001

應該當一個係姐姐 一個細佬咁諗?

仲有個好出名嘅conditional prob係玩患病人數
好似好耐之前見過有份mock出佢

咁樣先係一條出得街既問題
今朝果條係唔會有人答3/4😓

係呀

Diagnosis題
Joint us mock好似出過

不過最fake嘅題目係Monte hall problem

三門問題
我中學雞個時聽完都諗左陣

https://www.youtube.com/watch?v=6WuTNMleuQI

題目係choose左先再given that兩個係H
你2入面係揀淨呢四個case再任抽
有微妙分別

其實上面位巴打(a)係唔關事
問題係(b)既詮譯方法

wiki入面兩種詮釋我都覺得係正確，反正如果有咩唔清楚，解釋既責任應該係出題人果度
但考評局出既題，印象中佢所有"given XXX, find probability"都唔會係偶發式發現

https://lihkg.com/thread/993196/page/1

開定先
可能一訓醒就爆左

因為做個陣一時load唔到要咁做 做完之後先sub返 之後比學校老師扣左分
想知出去marker係咪兩個方法都收
有冇巴打係考評局marker

其實簡單d泥講一開頭睇果2個箱點都冇可能關第3個箱事，唔理佢係random抽定標籤左1/2/3號箱都係咁話
點解佢可以直接數HHH HHT HTH THH其中3個case有T就當佢係3/4，點講都唔會通😑

咁呢d就一定係咁計...好formal既

Two unbiasd coin are flipped into two boxes, one of the boxes is randomly selected. Given the coin in selected box is head, find the probability that remaining coin is tail.
所以你覺得會係1/2?

係

兩個箱個結果independent架嘛

1. Two unbiased coin are flipped, one is randomly selected, given the selected one is head, find the probability of the remaining one is tail?

2. Two unbiased coin are flipped, given one of them is head, find the probability of the remaining one is tail?
咁又點睇

1. 1/2
2. 2/3

試搶#1000