推 C2H:非常謝謝^^ 06/12 21:59
※ 引述《C2H (christine81420)》之銘言：
: 想請教一個數 學問題
: Q33:
: A photographer
: will arrange 6 people of 6 different heights
: for photograph by placing them in two rows of three so that
: each person in the first row is standing in front of someone
: in the second row. The heights of the people within each row
: must increase from left to right, and each person in the second
: row must be taller than the person standing in front of him or her.
: How many such arrangements of the 6 people are possible?
: A. 5
: B. 6
: C. 9
: D. 24
: E. 36
: 答案是A 不清楚怎麼得到的
: 想請教一下
: 謝謝^^
身高高度由左到右增加，第二排的又會比第一排高
可以分成以下幾種:
456 246 346 256 356
123 135 125 134 124
最矮的1和最高的6不要變，其他只要按照題目給的就可以囉! ^_^
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