1】用ci代表每個格。 |
送交者: zhf 2019月04月01日22:48:31 於 [靈機一動] 發送悄悄話 |
回 答: 趣味的數學-36【概率論】 由 gugeren 於 2019-03-30 19:36:09 |
用ci代表每個格。 P(3 in line) = Sum(i=1,64)[P(3 in line | 1st at ci)P(1st at ci)]= (1/64)Sum(i=1,64)[P(3 in line | 1st at ci)]= (1/64)Sum(i=1,64)[P(3 in V line + 3 in H line | 1st at ci)] = (1/64)Sum(i=1,64)[((7,2)+ (7,2))/(63,2)]= ((7,2)+ (7,2))/(63,2) |
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實用資訊 | |