Lying monkey

From Math Puzzle Wiki
Jump to navigation Jump to search
The printable version is no longer supported and may have rendering errors. Please update your browser bookmarks and please use the default browser print function instead.

You are a contestant on the hit game show "Lying Monkey." You are shown a hat which contains 80 folded $1 bills and 20 folded $5 bills. The trained talking monkey reaches in to the hat and pulls out a folded bill, but you cannot see whether it is a 1 or a 5. The monkey tells you that the bill is a 1, but from watching the show, you know that the monkey lies 30% of the time. What is the probability that the monkey is actually holding a $5 bill?