我有啲懷疑老師唔識英文

俾new comers
#148同#160有正確答案同解題思路

以你個老師嘅問題，唯一嘅答案只有1/2，因為佢係問阿joe嘅sibling係男嘅機率，而阿joe嘅sibling只有一個人所以係1/2。

係佢出錯左題目

高手

但係你prove唔到我呢個理解係錯誤
而你只係猜度題目想問的野的其中一個可能性

我仲諗緊 點樣可以解釋埋1/2

#148 唔敢講真係正確

利申 ：我係148

如果你要分次序，就會係b1b2, b2b1, b1g2, g1b2, g1g2, g2g1

假設joe係b, 1指大，2指細

點會兩個男就唔洗分大細

順便起置頂留言下補充返問題核心

老師以為題目講緊case2, 不過我覺得應該係case1

正如話一個人嘅性別係Facts定係Opinion一樣

睇落就應該啱


1／2咪一係男一係女

如果用1/3個答案，個邏輯本身就會雙重標準，兩個都係男時無計到joe係大仔定細仔兩個可能性，所以點都係錯

屌, 上面一早咪有人解左1/3同1/2點計啦, 你地只係重複緊佢地的argument然後一味話1/2錯

但係如果計埋大細次序嘅話會唔會係咁

p(哥&Joe,Joe&弟，Joe&妹，Joe&姐）=1/2

文字上根本無歧義，因為如果要分大細，點解兩個男時就唔洗分

唔洗理次序嘅話就係1/2?
理次序先1/3?

不過老實講 probability問題本來就好易有歧意，本身文字既邏輯性就表達唔到數學既複雜性（除非係德文/俄文果d時態格數勁清晰既語言）

所以正路係出長問題 寫步驟+解釋，你解得通就啱

1/3個計法根本係自打嘴巴，兩個都係男時無分大細

因為題目無要求
所以呢兩個組合都係ok

可以睇#148

仲有跨性別應該計brother/sister?

睇標題以為係英文題
睇樓主以為係數學題
睇解題原來係論理題
睇黎真係溫錯科入錯考場

無要求?一男一女你有分大細,你條友慣咗雙重標準

佢個老師以為自己問緊at least 1 boy
但係佢嘅寫法出到嚟係 上面 boy girl paradox入面嘅case 1
咁就奶嘢

咁1／2又真係只係文字遊戲
而唔係條題目真正想考嘅野

當然你可以講係題目寫得衰在先

大家係想探究條題目真正想考嘅野

The probability that Joe's sibling is a brother is 100%. If the neighbor has 2 children and one of them is a son, Joe, then the other child is either a son or a daughter. Since the question specifically asks about the probability that the sibling is a brother, the answer is 100%.

AI

有, 如果佢無講話佢有個仔叫呀Joe一般人對件事的理解會唔同
當然你提出的係另一個問題

我意思係如果條題目本身係:
There are two children, one of them is male.
應該唔會有咁大的理解分歧
但而家寫做
There are two children, one of them is a male, who is called Joe.
咁就可以有唔同理解

brother and sister is coexist for 男身女心 & 女身男心
they are brother and they are sister,at the same time
they could be anything