437概率简单数值题short

Fresh Start After a Losing Streak

题目

You flip a coin with $P(\text{heads}) = 1/3$ until you get heads. Given that the first 8 flips were all tails, what is the expected total number of additional flips needed (starting from flip 9)?

解题计时

0:00

提交作答时记录，用于后续平均用时统计。

你的答案

数值

支持题库 schema 允许的整数、小数、分数或四则表达式。