The drunk passenger
100 passengers board in order for 100 assigned seats. Passenger 1 lost their boarding pass and sits in a uniformly random seat. Each later passenger takes their own seat if it's free, otherwise a random free seat. What is the probability that passenger 100 ends up in their own seat?
Show hints (2)+
- Only two seats ultimately matter: seat 1 and seat 100.
- Argue by symmetry which of them is taken first.
Answer
Reveal answer →Final answer
0.5
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Asked at: Jane Street, Citadel, Two Sigma