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一道排列组合题，~~~~求救
Q33:
A photographerwill 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
绿色的为正确答案 |
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