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A队三男三女 要排成一圈(?)组成男女男女男女的阵容 问多少种方法
M1 M2 M3 F1 F2 F3 in a circle to get MFMFMF in a circle configuration
What we can do is the following, first we form a straight line. We can pick a M then a F then a M then a F. Then we use the line to form the circle.
Possibilities to form the line = 3*3*2*2 =36. However for a given circular formation of M1F1M2F2M3F3, it corresponding to 6 different linear formations including M1F1M2F2M3F3M1, M2F2M3F3M1F1, and M3F3M1F1M2F2. So we overcount by 3 times.
36/3 = 12. Only 12 combinations.
So the total is 12. |
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