There are 4 people in a closed room and you are waiting outside to enter
into the room. You can enter only when one of them opens the door. The
probability that somebody will open the door is 1/2. Now what is the
probability that the door will be opened so that you can go inside?
是50%吗？
s*******s 发帖数: 1568
2
P(O)=P(1U2U3U4) = 1-P(1&2&2&4)6
=15/16
【在 k******d 的大作中提到】 : There are 4 people in a closed room and you are waiting outside to enter : into the room. You can enter only when one of them opens the door. The : probability that somebody will open the door is 1/2. Now what is the : probability that the door will be opened so that you can go inside? : 是50%吗？
