乘着很多天才在此，问一个问题

来源: 于 2012-12-28 17:39:06 [博客] [旧帖] [给我悄悄话] 本文已被阅读：次

Can you solve this problem in less than 5 minutes?

A standard cubical die is thrown four times, with respective outcome a,b,c,d. what is the probability that  a≤b≤c≤d ?

 

 

ab≤c≤d