- 精华
- 0
- 积分
- 730
- 经验
- 730 点
- 威望
- 72 点
- 金钱
- 72 ¥
- 魅力
- 72
|
数学GWD1-Q25,真心没懂,求解释...
Q25:
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
6个人的高度都不一样,还要按照文中所述排列,不是应该只有一种排列方式了吗?!真心没懂啊... |
|