推 jackch458:看題意解釋吧 感覺那拿三個玩具的小孩是指定的了 10/14 21:48
→ KAINTS:如果不看答案，題意哪裡有說到指定呢??? 10/14 21:56
→ KAINTS:有什麼關鍵字嗎? 10/14 21:56
→ yyc1217:我覺得是你的答案才對~ 10/14 22:26
A father buys nine different toys for his four children.
In how many ways can he give one child three toys and the
remaining three children two toys each?
我的想法是先分堆再給物品(3,2,2,2)因為四個小孩都有可能
得到3個玩具所以我在乘上4!/3!=4,得到
4*(9C3)*(6C2)*(4C2)*(2C2)=30240
但答案卻是9!/3!2!2!2!=7560,為什麼他沒考慮
不同人取得三玩具之情形?
感謝回答
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