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        riddles >> easy >> Missing a Dollar? Need Help!
        
(Message started by: Pansita77 on Apr 20^th, 2004, 3:58pm)

Title: Missing a Dollar? Need Help!
Post by Pansita77 on Apr 20^th, 2004, 3:58pm

Probably a simple riddle to all - little ol' me having some issues.

Ok: Three guys pitch in $10 each for a $30 room for one night. Later on that evening the very kind manager realizes these men have payed regular price for a discounted room - on sale for $25 a night. He orders an employee to return the credit of $5 to the gentelmen - instead of returning the whole amount, the employee decides to keep 2 bucks for himself and gives ??? ??? the remaining $3 to the men. The men divide the 3 between themselves - a buck each meaning that they have actually payed $9 each for the room. So if each man actually payed 9 bucks each - the total payed between the 3 is $27 plus the $2 the employee took equals $29...where the hell is that last dollar damit!!!!

Title: Re: Missing a Dollar? Need Help!
Post by Icarus on Apr 20^th, 2004, 4:44pm

This one has been posted several times in the forums, and is one William put on his main list (hard section). This is a very well known puzzle. I have seen it numerous times in many different places.

The answer is, there is no last dollar. The 2 dollars the bellhop keeps are part of the $27 dollars paid by the three men, and should not be added to it. The division of the original $30 dollars is:

$3 to the three men, leaving $27 (= the 3 x $9 they ultimately paid).
$2 from the $27 for the bellhop, leaving $25.
$25 to the hotel.

Title: Re: Missing a Dollar? Need Help!
Post by Benoit_Mandelbrot on Apr 21^st, 2004, 10:23am

Interesting. This is in the easy forum, but in the hard puzzles. It's actually kind of easy to solve if you know something about math.

Title: Re: Missing a Dollar? Need Help!
Post by Icarus on Apr 21^st, 2004, 6:43pm

William has long since decided he placed that one in the wrong section. Actually, I moved this particular thread here from the General problem solving forum, since that one is not really for riddles.

It doesn't really need even much math knowledge. It just needs a little application of common sense to a calculation that has a tendency to blindside people. There is something about this calculation where-in the error falls into an area that we tend to not check, while it treats the areas we do check accurately. It takes a bit of training to break out of that mental rut and look at the whole thing. That is what this riddle is good for, and why it is still around despite being very old.