181概率简单数值题short
Coupon Collector with Four Types
题目
A cereal box contains one of 4 equally likely coupon types. You buy boxes one at a time. What is the expected number of boxes you must buy to collect all 4 types?
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
题目
A cereal box contains one of 4 equally likely coupon types. You buy boxes one at a time. What is the expected number of boxes you must buy to collect all 4 types?
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