| Hint |
| 送交者: 车五进二 2019月12月16日11:59:34 于 [灵机一动] 发送悄悄话 |
| 回 答: 趣味的数学-201 由 gugeren 于 2019-12-13 00:36:12 |
|
In a lineup of 20 people, there are 19 possible spots where the B/G combination could exist, and each of those spot must have the same probability, multiply that probability with 19 will yield the expected value, or average number of the occurance of B/G in the lineup. |
|
|
|
|
 |
 |
| 实用资讯 | |
