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Where's the change?

  1. Nov 13, 2005 #1
    Three men go to a hotel and decide to share a room. The room costs $30 per night, so they each leave $10 at reception and head upstairs.

    Later the concierge recalls that tonight is the twenty-five-dollar special. He gives the bell hop exactly five one-dollar coins(/notes, depends on your currency!).

    The bell hop arrives at the room and explains the special. The men realise there is no easy way to share the 5 coins between them, so they keep one dollar each and give the bell hop a $2 tip.

    Later, one of the men exclaims: "Wait, we got $1 back each, right? Well, that means we paid $9 each for the room, right? (Our original $10 each minus the dollar we got back.) Now, three nines is 27, plus the $2 tip gives $29. Where'd the other dollar go!?!"

    Where, indeed, did the extra dollar go?
    Last edited: Nov 13, 2005
  2. jcsd
  3. Nov 13, 2005 #2


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    Oh this is so old :P
  4. Nov 13, 2005 #3
    I concur.
  5. Nov 13, 2005 #4


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    Its fairly obvious that the 2nd man ate the money
  6. Nov 14, 2005 #5
    Government tax.
  7. Nov 14, 2005 #6
    try thinking of it this way: 3 guys go to rent a room. it costs 25 a night. to make it even they each pay 9 dollars and say keep the change. 3*9=27total=25rent+2tip. they didn't pay 27+2.
  8. Nov 14, 2005 #7
    Must be a sign of the times, these 3 guys used to just go out for a meal, now they're sharing a room for the night!
  9. Nov 14, 2005 #8
    It's easy! the question is set up to mislead you... it's really like this... 30$ is payed... 5$ is given back (now we're at 25$ payed) ... 3 dollars are kept (now we're at 28!) 2 dollar tip! wala... 30$... each man does not actually pay the even 9 dollars each :P... but where indeed... does that extra penny go? It's only 25 dollars for the room! Why would they each pay 9 dollars? :P 8.33X3 is 24.99, kept 3, 27.99, 2 tip... 29.99... where is the extra penny? haha i suck at my futile attempts to keep this going.
    Last edited: Nov 14, 2005
  10. May 6, 2006 #9
    I am just a normal housewife.....no big education....but I would use the debit/credit theory....
    debit.....$27 disbursed collectively from the 3 men

    credit....$25 for the room and $2 tip.....

    No extra dollar floating around:rolleyes:
  11. May 6, 2006 #10


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    It's on wolfram's bed :rofl:
  12. May 18, 2006 #11


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    It's such an evil problem. They count the tip twice, it was already included in the 27$ and for some reason they add it again.
  13. May 19, 2006 #12
    It's an easy problem :)

    However, I should try to get some people with that type of logic....hmm
  14. May 24, 2006 #13
    I was a bit perplexed a first, I was wondering why he added the two dollars to 27 when he should have been subtracting it to get the cost of the room. Funny, misleading the person like so; I wonder how many of my friends will fall for it?
  15. Jun 7, 2006 #14


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    So how do I explain this to everybody so I sound smart?
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