Prob

y
youknow
楼主 (未名空间)

25% of the time you can get from your friend a free ticket of a game for a
sports season. You have to call your friend prior to each game and he will
let you know. You just woke up today and a game is just two days away, so
you call your friend, and he tells you there is a free ticket for you.
However, he lies to you 1/3 of the time. How likely is it that there is a
free ticket for you today?