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送交者: 車五進二 2019月12月16日11:59:34 於 [靈機一動] 發送悄悄話 |
回 答: 趣味的數學-201 由 gugeren 於 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. |
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