Probability [URGENT]

rainstars

There are three prisoners A, B and C, one of them will be randomly picked by the king to be freed, two others will be executed. The king wants the guard to keep secret on who will be freed. A, who wants to know whether he himself will be freed asks the guard, who, between B and C will be executed. The guard hence told A, “B will be executed”, thinking that he gives no useful information to A since at least one of B or C will be executed. From prisoner A point of view, does the probability of him being freed changed before and after the guard tell him the information?


救救我~谢咯！

Gaia

Guard還沒透露前：executed rate = 2/3, freed rate = 1/3
Guard透露后      ：executed rate = 1/2, freed rate = 1/2

rainstars

可是这个题目有点类似monty hall和three prisoners problem，真的就会那么简单？？

雨不停

24号就快到了。。。hahaha

陈星星

这是我的看法loh

1)B & C executed, A freed
2)A & C executed, B freed
3)A & B executed, C freed