Emptying the cherry bowl
A bowl has red and purple cherries. Cherries are removed one at a time, uniformly at random, and you stop once no red cherries remain. What is the probability that the bowl is completely empty when you stop (i.e. the last red is removed only as the very last cherry)?
Show hints (2)+
- The bowl is empty at the stop iff no purple cherry sits after the last red - i.e. the last cherry drawn is red.
- By symmetry the last cherry is a uniformly random one of the .
Answer
Reveal answer →Final answer
0.3846 (± 0.001)
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Asked at: Jane Street, Optiver