- 精华
- 1
- 积分
- 1469
- 经验
- 1469 点
- 威望
- 146 点
- 金钱
- 146 ¥
- 魅力
- 146
|
问一道数学题排列组合的
Each of the integers form 0 to 9, inclusive, is written on a separate slip of bland paper and the ten slips are dropped into a hat. If the slips are then drawn one at a tim
e without replacement, how many must be drawn to ensure that the numbers on two of the slips drawn will have a sum of 10?
谢谢 |
|