A Problem With Pearls
Probability puzzles require you to weigh all the possibilities and pick the most likely outcome.
"I'm a very rich man, so I've decided to give you some of my fortune. Do you see this bag? I have 5001 pearls inside it. 2501 of them are white, and 2500 of them are black. No, I am not racist. I'll let you take out any number of pearls from the bag without looking. If you take out the same number of black and white pearls, I will reward you with a number of gold bars equivalent to the number of pearls you took."
How many pearls should you take out to give yourself a good number of gold bars while still retaining a good chance of actually getting them?
HintIf you took out 2 pearls, you would have about a 50% chance of getting 2 gold bars. However, you can take even more pearls and still retain the 50% chance.
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Answer
Take out 5000 pearls. If the remaining pearl is white, then you've won 5000 gold bars!
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Comments
braingle100
Jan 03, 2011
 'no I a not racist.' LOL 
No_Eyed_Fsh
Jan 03, 2011
 This teaser was used in my recent WTB game, The Riddle Shop. No, it is not a riddle. 
BrainBoggler
Jan 13, 2011
 easy................ if that was me, i would have been sooooooooooooooooooooooooo rich!!!!! 
Stack1607
Jan 15, 2011
 great teaser! 
OpusthePenguin
Mar 21, 2016
 The proposed answer assumes that one would rather have a 50% chance of winning 5000 gold bars than a 50.02% chance of winning a single gold bar. That's an accurate assumption in my case, but it does mean this isn't purely a probability problem.
Let's tweak the problem slightly. Keep the reward the sameone gold bar per pearl withdrawn. But let's add in a penalty. If you don't withdraw an equal number of black and white pearls, you die. In that case, I'd suggest withdrawing two pearls since that would (very slightly) increase your chance of remaining alive. 
presensor
Mar 06, 2017
 The answer is not strict math proved. 
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