连续两/三正面：一般公式
Two heads in a row
题目详情
What is the expected number of tosses of an unfair coin needed to get two heads in a row (assume probability of a head)? Same question with three heads in a row.
解析
设正面概率为 。
连续两正面期望：
连续三正面期望：
一般连续 个正面：
Two heads in a row
What is the expected number of tosses of an unfair coin needed to get two heads in a row (assume probability of a head)? Same question with three heads in a row.
设正面概率为 。
连续两正面期望：
连续三正面期望：
一般连续 个正面：