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        riddles >> hard >> airplane riddle
        
(Message started by: benmartorano on Oct 5^th, 2012, 3:03pm)

Title: airplane riddle
Post by benmartorano on Oct 5^th, 2012, 3:03pm

People are waiting in line to board a 100-seat airplane. Steve is the first person in the line. He gets on the plane but suddenly can't remember what his seat number is, so he picks a seat at random. After that, each person who gets on the plane sits in their assigned seat if it's available, otherwise they will choose an open seat at random to sit in.
The flight is full and you are last in line.

What is the probability that you get to sit in your assigned seat?

Title: Re: airplane riddle
Post by Altamira_64 on Oct 10^th, 2012, 11:40am

Let's start by saying that Steve will sit in his own place with probability 1%.
Then the second passenger will sit in his assigned seat with probability 99%.

Title: Re: airplane riddle
Post by towr on Oct 10^th, 2012, 1:15pm

I don't think the logic of that is correct; although the conclusion it leads to is.
There is a 1% probability that Steve will sit in the second passengers seat and therefor the second passenger has a 99% chance of sitting in his assigned seat. (i.e. not because Steve has a 1% chance of sitting in his own seat, but because of the 1% chance of him sitting in the second's seat)

Anyway, here's (http://www.ocf.berkeley.edu/~wwu/cgi-bin/yabb/YaBB.cgi?board=riddles_easy;action=display;num=1067088849) a previous thread for this puzzle.

Title: Re: airplane riddle
Post by Altamira_64 on Oct 11^th, 2012, 8:20am

I see.
Thanks for posting the link to the other thread.