# Riddle...Any takers?

**URL:** <https://boards.straightdope.com/t/riddle-any-takers/42249>\
**Category:** Miscellaneous and Personal Stuff I Must Share\
**Created:** [November 22, 2000, 5:20am UTC](https://boards.straightdope.com/t/riddle-any-takers/42249 "2000-11-22T05:20:58Z")\
**Posts on this page:** 14\
**Page:** 1

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**Author:** ![Just\_A\_Girl](https://avatars.discourse-cdn.com/v4/letter/j/5daacb/32.png) [@Just\_A\_Girl](https://boards.straightdope.com/u/Just_A_Girl)\
**Post date:** [November 22, 2000, 5:20am UTC](https://boards.straightdope.com/t/riddle-any-takers/42249/1 "2000-11-22T05:20:58Z")

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Ok…my psychology teacher was kicking himself today because he couldn’t figure this riddle out. While the answer can be arrived at by logic, there’s not a definant answer but rather an explaination which is hard to simplify. (Well…for me anyway) Here it is:

3 men go to check into a hotel. The guy at the counter tells them that it will be $30 for one room. The men decide to share a room, and split the cost evenly; that is, each man pays $10. Later into the evening, the “behind-the-counter guy” discovers that the room was actually $25, not $30, and immediately sends a bellhop to the room with $5. The bellhop realizes it will be difficult to split $5 three ways so he pockets $2, and gives each man back $1. This means that each man has now paid $9 in his share of the room instead of $10. However, $9 multiplied by 3 is $27. Adding in the bellhop’s pocketed $2, that makes a total of $29. So where’d the other dollar go?

While I know the basic idea of why this is so, I want to know if anyone has heard this riddle before and maybe has seen a simplified answer? Anyone else, give it a try!

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**Author:** ![dpr](https://avatars.discourse-cdn.com/v4/letter/d/8797f3/32.png) [@dpr](https://boards.straightdope.com/u/dpr)\
**Post date:** [November 22, 2000, 5:23am UTC](https://boards.straightdope.com/t/riddle-any-takers/42249/2 "2000-11-22T05:23:55Z")

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Oh god. Not again…

This starts arguments around here. Just don’t ask about the three doors and the odds being 50-50 or 1 in 3 please…

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**Author:** ![SPOOFE](https://avatars.discourse-cdn.com/v4/letter/s/c5a1d2/32.png) [@SPOOFE](https://boards.straightdope.com/u/SPOOFE)\
**Post date:** [November 22, 2000, 5:26am UTC](https://boards.straightdope.com/t/riddle-any-takers/42249/3 "2000-11-22T05:26:10Z")

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[Homer Simpson]

“It’s a ring toss.”

[/Homer Simpson]

(Hint: You don’t multiply the numbers at the end. 30-5=25. 25+3=28. 28+2=30)

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**Author:** ![Sublight](https://avatars.discourse-cdn.com/v4/letter/s/439d5e/32.png) [@Sublight](https://boards.straightdope.com/u/Sublight)\
**Post date:** [November 22, 2000, 5:26am UTC](https://boards.straightdope.com/t/riddle-any-takers/42249/4 "2000-11-22T05:26:30Z")

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Try here:

[http://www.straightdope.com/classics/a910621.html](http://www.straightdope.com/classics/a910621.html)

–sublight.

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**Author:** ![Danalan](https://avatars.discourse-cdn.com/v4/letter/d/76d3ee/32.png) [@Danalan](https://boards.straightdope.com/u/Danalan)\
**Post date:** [November 22, 2000, 5:26am UTC](https://boards.straightdope.com/t/riddle-any-takers/42249/5 "2000-11-22T05:26:46Z")

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Haven’t you heard this one before? It is a fairly well-known example of false logic.

The key is in the two additions, which should be separate. The men indeed paid $9 each for the room, for a total of $27. However, one should not add the bellboy’s $2 to that amount, but subtract the $2 from the $27 to get $25, the actual amount charged.

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**Author:** ![Kat](https://avatars.discourse-cdn.com/v4/letter/k/b19c9b/32.png) [@Kat](https://boards.straightdope.com/u/Kat)\
**Post date:** [November 22, 2000, 5:27am UTC](https://boards.straightdope.com/t/riddle-any-takers/42249/6 "2000-11-22T05:27:13Z")

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Simplified:  
Hotel keeps: $25  
Bellboy keeps: $2  
Man #1 keeps: $1  
Man #2 keeps: $1  
Man #3 keeps: $1  
Total: $30

(25 + 2 + 1 + 1 + 1=30)

The way the “riddle” is worded, you count the bellboy’s $2 twice and don’t count the three men’s $1 each ($3 total) at all.

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**Author:** ![Just\_A\_Girl](https://avatars.discourse-cdn.com/v4/letter/j/5daacb/32.png) [@Just\_A\_Girl](https://boards.straightdope.com/u/Just_A_Girl)\
**Post date:** [November 22, 2000, 5:28am UTC](https://boards.straightdope.com/t/riddle-any-takers/42249/7 "2000-11-22T05:28:47Z")

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I didn’t say anything about odds or doors! Seriously, I’m asking because I told my teacher I’d post it and see what people said. He was going nuts over this thing. I’m not trying to cause a problem…I’m just an innocent little girl! 😉

For dpr’s sake guys…don’t get all bent out of shape over it…I’m just curious!

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**Author:** ![Just\_A\_Girl](https://avatars.discourse-cdn.com/v4/letter/j/5daacb/32.png) [@Just\_A\_Girl](https://boards.straightdope.com/u/Just_A_Girl)\
**Post date:** [November 22, 2000, 5:31am UTC](https://boards.straightdope.com/t/riddle-any-takers/42249/8 "2000-11-22T05:31:40Z")

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> [@](#):
>
> \*Originally posted by Danalan \*  
> \*\*Haven’t you heard this one before? It is a fairly well-known example of false logic.
> 
> The key is in the two additions, which should be separate. The men indeed paid $9 each for the room, for a total of $27. However, one should not add the bellboy’s $2 to that amount, but subtract the $2 from the $27 to get $25, the actual amount charged. \*\*

awesome…that’s what I’m looking for. See, I figured out the whole adding thing and the “false wording.” But the nature of logic problems is to have a more simple explanation and that’s exactly it. Thanks a ton. 😃

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**Author:** ![Danalan](https://avatars.discourse-cdn.com/v4/letter/d/76d3ee/32.png) [@Danalan](https://boards.straightdope.com/u/Danalan)\
**Post date:** [November 22, 2000, 5:36am UTC](https://boards.straightdope.com/t/riddle-any-takers/42249/9 "2000-11-22T05:36:45Z")

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Glad to help.

(sigh of relief that I seem to have gotten it right, and so avoid the wrath of the collective SDMB)

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**Author:** ![Mac\_Guffin](https://avatars.discourse-cdn.com/v4/letter/m/2bfe46/32.png) [@Mac\_Guffin](https://boards.straightdope.com/u/Mac_Guffin)\
**Post date:** [November 22, 2000, 7:17am UTC](https://boards.straightdope.com/t/riddle-any-takers/42249/10 "2000-11-22T07:17:43Z")

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Back when I had to do math for a living, someone told me this riddle, and it took me almost a full day and night to figure it out. I came apon the answer in bed, at 4 am while staring at the ceiling going insane from it.

Before I arived at the correct answer covered here, I also came up with this false answer.

Later that same night, Two more guys check into the same motel, are told the room is $30 and decide to split it by paying $15 each. Later the “behind the counter guy” realizes that he made the mistake again, and calls the bellhop back with another $5 in $1 bills. the Bellhop, now overcome with greed from the earlier money, takes three dollars and gives each of the two guys a dollar each.

so each man, having paid $14 times two, paid a total of $28 dollars, plus the three the bellhop kept makes $31. there’s yer extra dollar you lost earlier.

I realize that the same false logic applies here, but that one almost made my brain leave my head for good.

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**Author:** ![dpr](https://avatars.discourse-cdn.com/v4/letter/d/8797f3/32.png) [@dpr](https://boards.straightdope.com/u/dpr)\
**Post date:** [November 22, 2000, 7:45am UTC](https://boards.straightdope.com/t/riddle-any-takers/42249/11 "2000-11-22T07:45:01Z")

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Sorry JaG, it’s just that some of the logic problems posted here have started wars (or at least minor revolutions).

I was scared… nothing personal…

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**Author:** ![Jack\_Batty](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jack_batty/32/3201_2.png) [@Jack\_Batty](https://boards.straightdope.com/u/Jack_Batty)\
**Post date:** [November 22, 2000, 4:38pm UTC](https://boards.straightdope.com/t/riddle-any-takers/42249/12 "2000-11-22T16:38:19Z")

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Just A girl, you left out the most important part of the riddle.

The name of the hotel is **The Gry Inn** , which in itself answers at least one other question.

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**Author:** ![c\_goat](https://avatars.discourse-cdn.com/v4/letter/c/f4b2a3/32.png) [@c\_goat](https://boards.straightdope.com/u/c_goat)\
**Post date:** [November 22, 2000, 4:43pm UTC](https://boards.straightdope.com/t/riddle-any-takers/42249/13 "2000-11-22T16:43:01Z")

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> [@](#):
>
> \*Originally posted by Just A Girl \*  
> **Ok…my psychology teacher was kicking himself today because he couldn’t figure this riddle out.**

That’s pretty bad. I think the SD will never eradicate ignorance as long as this “riddle” keeps circulating.

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**Author:** ![AWB](https://avatars.discourse-cdn.com/v4/letter/a/bb73d2/32.png) [@AWB](https://boards.straightdope.com/u/AWB)\
**Post date:** [November 22, 2000, 5:36pm UTC](https://boards.straightdope.com/t/riddle-any-takers/42249/14 "2000-11-22T17:36:21Z")

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> [@](#):
>
> \*Originally posted by Just A Girl \*  
> \*\*Ok…my psychology teacher was kicking himself today because he couldn’t figure this riddle out. While the answer can be arrived at by logic, there’s not a definant answer but rather an explaination which is hard to simplify. (Well…for me anyway) Here it is:
> 
> 3 men go to check into a hotel. The guy at the counter tells them that it will be $30 for one room. The men decide to share a room, and split the cost evenly; that is, each man pays $10. Later into the evening, the “behind-the-counter guy” discovers that the room was actually $25, not $30, and immediately sends a bellhop to the room with $5. The bellhop realizes it will be difficult to split $5 three ways so he pockets $2, and gives each man back $1. This means that each man has now paid $9 in his share of the room instead of $10. However, $9 multiplied by 3 is $27. Adding in the bellhop’s pocketed $2, that makes a total of $29. So where’d the other dollar go?
> 
> While I know the basic idea of why this is so, I want to know if anyone has heard this riddle before and maybe has seen a simplified answer? Anyone else, give it a try! \*\*

This is because he’s adding together the wrong dollars.

The $27 that the guests paid for the room consists of the $25 that front counter has plus the $2 that the bellhop kept. To that, he’s re-adding the $2 that the bellhop kept. This doesn’t represent the total.

Or algebraically: Divide the $30 into three parts:  
Let  
A = Final charge for room ($25)  
B = Amount that bellhop kept ($2)  
C = Amount refunded to men ($3)

so A + B + C = 30

But the riddle is basically asking why:  
(A + B) + B \<\> 30

Of course it doesn’t, because it doesn’t include C and it double-includes B.
