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Timeline for Taking Seats on a Plane

Current License: CC BY-SA 4.0

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Sep 1, 2021 at 7:58 comment added user851668 @DanielV Thanks! But how can I intuit $p_{k}={1\over n}+p_2{1\over n-1}+p_3{1\over n-2}\dots+p_{k-1}{1\over n-k}$? I still don't understand where this expression hails from! It feels like it appeared from left field! Can you de-mystify this to a 16 y.o.?
Aug 23, 2021 at 11:49 comment added DanielV @KSLLF $1/n$ is the probability that the first person sits in seat $k$. The probability that person $j$'s seat is taken is $p_j$, and there are are $(n - j + 1)$ seats then he will choose from, $1$ of them is person $k$'s seat.
Aug 23, 2021 at 7:58 comment added user851668 @DanielV 2. I know that "each term (except the first)" is "the probability that person j's seat is taken and he sits in seat k". But why's this $p_j \cdot (n - j + 1)^{-1}$?
Aug 23, 2021 at 7:57 comment added user851668 1. In your equation for $p_k$, what does $1/n$ (the first term) signify? Pls edit your answer to clarify.
Aug 1, 2021 at 18:04 comment added DanielV Just to clarify, each term (except the first) is "the probability that person j's seat is taken and he sits in seat k", $p_j \cdot (n - j + 1)^{-1}$ , which are a complete list of ways person k's seat could be taken and all of them are disjoint, so it is correct to add them.
Feb 1, 2021 at 9:56 review Late answers
Feb 1, 2021 at 10:11
Feb 1, 2021 at 9:39 history answered user43170 CC BY-SA 4.0