Mad old lady riddle

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	Ant_222  #544670  Mon, 21 Jul 08 10:32 PM Here's another riddle that may serve as five-minute excersize for your gray cells...  There's a queue of twenty people to a twenty-seat bus, and a mad old lady is first in the queue. And, due to her mental illness, she chooses a random seat instead of the one specified on her ticket. The others board the bus one after another trying to take their own seat, but, if they find it occupied, they have nothing to do than choose a random seat of those that are still vacant. Ant the question is, what are the chances for the last person in queue to take their own seat?    Ant_222 Joined on Sun, May 21 2006 Podolsk, Russia Contributing Member (1,547)
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	Anonymous  #544835  Tue, 22 Jul 08 04:43 AM 1 out of 20    Anonymous

	Ant_222  #544878  Tue, 22 Jul 08 07:44 AM Guessing or what? That's wrong!    Ant_222

	Insider  #544966  Tue, 22 Jul 08 01:40 PM Hm, i think it is 50/50? There is only one place left for the last person, so it is either his/hers or not. But im not sure, hm tough, aye.    Insider Joined on Mon, Jul 18 2005 Auckland, NZ Junior Member (87) M.A.Q.

	Ant_222  #545034  Tue, 22 Jul 08 03:58 PM Hmmm. I might as well say I have 50/50 chances of meeting a dinosaur... Either I meet one or not.    Ant_222

	Grammar Geek  #545038  Tue, 22 Jul 08 04:11 PM Is it 19/20 x 18/19 x 17/18, etc? until you're at 1/2?      Grammar Geek Joined on Tue, Jan 10 2006 Pennsylvania, USA Veteran Member (15,583) Barbara, who answers in American English.

	Ant_222  #545067  Tue, 22 Jul 08 06:58 PM GG: I am not sure you'll end up with 1/2 that way. Rather, you'll get 1/20 in the end, which is not correct ;)    Ant_222

	Grammar Geek  #545070  Tue, 22 Jul 08 07:02 PM No, I mean 19/20 x 18/19 x 17/18 .... 2/3 x 1/2      Grammar Geek

	Ant_222  #545078  Tue, 22 Jul 08 07:17 PM GG: Then, as I said, it equals 1/20. (Every number in the production has a pair except the 20 in the denominator and the 1 in the numerator)    Ant_222
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