# Is there a word for this type of brainteaser?

**URL:** https://boards.straightdope.com/t/is-there-a-word-for-this-type-of-brainteaser/996426
**Category:** Miscellaneous and Personal Stuff I Must Share
**Created:** [January 21, 2024, 4:27am UTC](https://boards.straightdope.com/t/is-there-a-word-for-this-type-of-brainteaser/996426 "2024-01-21T04:27:03Z")
**Posts on this page:** 20
**Page:** 1

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### Author: ![RickJay](https://avatars.discourse-cdn.com/v4/letter/r/bb73d2/32.png) [@RickJay](https://boards.straightdope.com/u/RickJay)
#### Post date: [January 21, 2024, 4:27am UTC](https://boards.straightdope.com/t/is-there-a-word-for-this-type-of-brainteaser/996426/1 "2024-01-21T04:27:03Z")

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I saw this on Facebook. It seems easy but seems to fool people:

“I bought a reindeer for $900 and sold it for $1300. I bought it back for $1400 and sold it for $1700. What profit did I make?”

The answer is $700, which seemed obvious to me, but it REALLY throws people. the most common answer is $600, which is demonstrably wrong, but you can kind of understand why people get that; they seem to assume buying another product for $100 more than the first sale price means a loss and they tend to double count that $100.

It reminded me of a very famous old riddle; three men check into a hotel. They are charged $30 for a room they will share, so each pays $10. The desk clerk realizes he erred and the room was only $25, so he gives a bellboy $5 in singles to give back to the men. The bellboy says the hell with it, tells them it was $27 and gives each $1 back, keeping $2 for himself. Since each man has now paid $9, 3x9 is 27, and the bellboy has $2, and 27+2 is 29, where’s the missing dollar? The answer is there isn’t one. The men spent $27, $25 on the room, $2 to the thieving bellboy. You can’t add 27 to 2 at all. The 2 is PART of the 27.

Both these riddles rely on confusing you by making unrelated numbers seem related. In Riddle 1, the reindeer being sold for $1300 and repurchased for $1400 makes you think that $100 difference matters, but it’s not a relevant number at all. (The illusion is swiftly broken if you just charge the wording to say it’s two different reindeer, or two totally different products, as one might buy in a store.) The second problem tricks you into counting a number twice.

Another similar riddle; a thief enters a store. He steals $100 from the register. He then uses the $100 to purcahse a $70 item, and leaves with the item and $30 in change. How much did he steal? Clearly, he stole $100 - an accountant will tell you it’s absolutely just $100 cash, that no goods were stolen, and she’d be right, but if you want to insist it’s $30 in cash and $70 in goods I won’t bother arguing, because the amazing thing is many people will SWEAR the thief stole $200, $130, or $170.

Is there a word for this type of math puzzle - a puzzle where the arithmetic is actually simple but the wording and closeness of numbers can throw people?

Know any others?

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### Author: ![Beckdawrek](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beckdawrek/32/3647_2.png) [@Beckdawrek](https://boards.straightdope.com/u/Beckdawrek)
#### Post date: [January 21, 2024, 4:29am UTC](https://boards.straightdope.com/t/is-there-a-word-for-this-type-of-brainteaser/996426/2 "2024-01-21T04:29:34Z")

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I don’t know an official name for it…we called them _word problems_ in 5th grade.  
I know I hated the hell outta them.

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### Author: ![Darren\_Garrison](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darren_garrison/32/92_2.png) [@Darren\_Garrison](https://boards.straightdope.com/u/Darren_Garrison)
#### Post date: [January 21, 2024, 4:38am UTC](https://boards.straightdope.com/t/is-there-a-word-for-this-type-of-brainteaser/996426/3 "2024-01-21T04:38:24Z")

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I see some mentions calling them wordy math problems.

> **[How to Solve a Wordy Math Problem (with Pictures) - wikiHow Life](https://www.wikihow.life/Solve-a-Wordy-Math-Problem)**
>
> As your math skills advance, you will begin to encounter longer and longer word problems. Often these problems contain extraneous information that is not needed in order to solve the problem. These types of problem test your logic and math...

> **[Tackling Wordy Problems: How the Three Reads Math Language Routine Supports...](https://illustrativemathematics.blog/2022/08/09/tackling-wordy-problems-how-the-three-reads-math-language-routine-supports-access-for-all-learners/)**
>
> by Joe Herbert “These problems are great, but they’re just so wordy. My students can’t handle all that reading!” Does this feel familiar? If so, you’re not alone! Many students and teachers struggle with the language demands of IM 6–12 Math when they...

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### Author: ![Gatopescado](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gatopescado/32/5711_2.png) [@Gatopescado](https://boards.straightdope.com/u/Gatopescado)
#### Post date: [January 21, 2024, 5:53am UTC](https://boards.straightdope.com/t/is-there-a-word-for-this-type-of-brainteaser/996426/4 "2024-01-21T05:53:43Z")

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Idiot sold it the first time for way too little. Should have held out till that second buyer came around, and he would have made $800!

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### Author: ![pjd](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pjd/32/3009_2.png) [@pjd](https://boards.straightdope.com/u/pjd)
#### Post date: [January 21, 2024, 7:51pm UTC](https://boards.straightdope.com/t/is-there-a-word-for-this-type-of-brainteaser/996426/5 "2024-01-21T19:51:06Z")

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They’re sometimes called paradoxes.

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### Author: ![Dead\_Cat](https://avatars.discourse-cdn.com/v4/letter/d/9fc29f/32.png) [@Dead\_Cat](https://boards.straightdope.com/u/Dead_Cat)
#### Post date: [January 21, 2024, 8:53pm UTC](https://boards.straightdope.com/t/is-there-a-word-for-this-type-of-brainteaser/996426/6 "2024-01-21T20:53:25Z")

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Inaccurately, in my view. A paradox is an actual contradiction in terms, these are just obfuscation.

I posted something along these lines a few years ago, that actually happened to me. The short version is, I was in a casino and placed a £100 bet on roulette, on red. The ball landed in a black number on that spin, but for whatever reason, the croupier didn’t clear my chip from the table. I left it there for the next spin, which came up red, and the croupier paid my winnings of £100, at which point I took £200 off the table, cashed out, and left. How much did I ‘steal’ from the casino? The responses were very interesting, but the only ones I totally rejected were those that suggested I had stolen £200.

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### Author: ![pjd](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pjd/32/3009_2.png) [@pjd](https://boards.straightdope.com/u/pjd)
#### Post date: [January 21, 2024, 9:03pm UTC](https://boards.straightdope.com/t/is-there-a-word-for-this-type-of-brainteaser/996426/7 "2024-01-21T21:03:58Z")

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> [@Dead\_Cat](#):
>
> Inaccurately, in my view.

Yes, they’re more often just called riddles.  
IMHO, regarding the casino scenario, you appear to have $200 which you shouldn’t  
(morally) have…

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### Author: ![Dead\_Cat](https://avatars.discourse-cdn.com/v4/letter/d/9fc29f/32.png) [@Dead\_Cat](https://boards.straightdope.com/u/Dead_Cat)
#### Post date: [January 21, 2024, 9:13pm UTC](https://boards.straightdope.com/t/is-there-a-word-for-this-type-of-brainteaser/996426/8 "2024-01-21T21:13:40Z")

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Had - I’ve been back many times since! 🙂

ETA: the reason I reject that notion is I could have placed a further £100 bet for the second spin, with my own money. I didn’t need to thanks to the initial oversight, but I’m only up £100 on the transaction.

Dont want to relitigate it all here, someone less lazy than me should be able to find the thread (I started it) if they want to bump it.

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### Author: ![Beckdawrek](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beckdawrek/32/3647_2.png) [@Beckdawrek](https://boards.straightdope.com/u/Beckdawrek)
#### Post date: [January 21, 2024, 9:16pm UTC](https://boards.straightdope.com/t/is-there-a-word-for-this-type-of-brainteaser/996426/9 "2024-01-21T21:16:42Z")

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I just ask the Lil’wrekker. Closer to grade school math than I am.  
She said one of her teachers called them _Story problems_ .

And, yes she hated them as well.

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### Author: ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)
#### Post date: [January 21, 2024, 9:20pm UTC](https://boards.straightdope.com/t/is-there-a-word-for-this-type-of-brainteaser/996426/10 "2024-01-21T21:20:16Z")

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> [@pjd](#):
>
> IMHO, regarding the casino scenario, you appear to have $200 which you shouldn’t  
> (morally) have…

Suppose that @Dead_Cat had picked up the $100 worth of chips after the dealer failed to collect them, and put them in their pocket. And suppose that they then put another $100 worth of chips back down on the table in preparation for the next spin. How is that any different from what did happen?

Alternately, suppose that @Dead_Cat had taken all of the same actions, but had lost the second spin, and this time the dealer collected the chips as they were supposed to. @Dead_Cat walks away empty-handed. Would you say in this case that they didn’t steal anything, since they walked away without it?

(and of course, the real answer is that they didn’t steal anything, because it was the casino’s responsibility to collect the losing chips, not the player’s)

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### Author: ![Dead\_Cat](https://avatars.discourse-cdn.com/v4/letter/d/9fc29f/32.png) [@Dead\_Cat](https://boards.straightdope.com/u/Dead_Cat)
#### Post date: [January 21, 2024, 9:25pm UTC](https://boards.straightdope.com/t/is-there-a-word-for-this-type-of-brainteaser/996426/11 "2024-01-21T21:25:22Z")

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I think this is what you said in the original thread: [Moral dilemma - gambling related](https://boards.straightdope.com/t/moral-dilemma-gambling-related/543359)

13.5 years ago, man. Please could we move this hijack to there? Apologies to the OP.

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### Author: ![RivkahChaya](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/rivkahchaya/32/8919_2.png) [@RivkahChaya](https://boards.straightdope.com/u/RivkahChaya)
#### Post date: [January 21, 2024, 9:48pm UTC](https://boards.straightdope.com/t/is-there-a-word-for-this-type-of-brainteaser/996426/12 "2024-01-21T21:48:31Z")

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> [@Beckdawrek](#):
>
> we called them _word problems_ in 5th grade.  
> I know I hated the hell outta them.

I **LOVED** word problems. Usually there were 20 or 25 problems on a homework page, but when there were word problems-- we called them “story problems”-- there’d be 4 or 5. Too easy.

While the puzzles are technically story/word problems, I think they are more than that. The kind of story problem in my math book was always straightforward-- Sue has 5 apples, and she gives 1 apple to Lou. How many apples does Sue have left?

The tricky problems the OP is presenting may require arithmetic, but they are logic puzzles.

When story problems and logic puzzles meet on the Venn diagram, these are what you have.

The Monty Hall problem is similar, in that while it doesn’t have mathematical terms in the story, it requires some basic math to get to the answer, but also the insight that Monty _knows_ where the prize is, and _never opens a door with the big prize._

This problem somehow is the Ur problem like this-- I mean, it can’t really be, since these have to go back before Monty Hall, but this seems to be the one everyone knows, and so they are actually referred to as “Monty Hall problems.”

If you define a Monty Hall problem as a “brainteaser with math,” then I’d call this one.

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### Author: ![Darren\_Garrison](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darren_garrison/32/92_2.png) [@Darren\_Garrison](https://boards.straightdope.com/u/Darren_Garrison)
#### Post date: [January 21, 2024, 9:57pm UTC](https://boards.straightdope.com/t/is-there-a-word-for-this-type-of-brainteaser/996426/13 "2024-01-21T21:57:12Z")

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> [@Beckdawrek](#):
>
> I just ask the Lil’wrekker. Closer to grade school math than I am.  
> She said one of her teachers called them _Story problems_ .

You are missing the point in both of your replies. He wasn’t asking what word problems are called, he was asking what word problems with tons of irrelevant information designed to be confusing are called.

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### Author: ![RivkahChaya](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/rivkahchaya/32/8919_2.png) [@RivkahChaya](https://boards.straightdope.com/u/RivkahChaya)
#### Post date: [January 21, 2024, 9:57pm UTC](https://boards.straightdope.com/t/is-there-a-word-for-this-type-of-brainteaser/996426/14 "2024-01-21T21:57:32Z")

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> [@Chronos](#):
>
> and of course, the real answer is that they didn’t steal anything, because it was the casino’s responsibility to collect the losing chips, not the player’s

Hah.

Since Dead Cat just picked up stray chips, and didn’t threat or coerce money from anyone, I wouldn’t call it theft.

Here’s a problem:

I was 11 when I was at the arcade of a ski resort with a friend, and we spotted two $50 bills on the floor and picked them up and pocketed them, did we steal?

I don’t think so.

But that isn’t the end of the story.

About 10 minutes later, we saw a couple clearly looking for something, and mostly over in the place where we had found the money.

If we kept it art that point, is it theft?

We thought it was, and asked the couple if they lost something (we didn’t say what). They said $100 in 2 fifties, and at that point we returned the money. The couple gave us each a $20. $20 guilt-free dollars.

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### Author: ![Thudlow\_Boink](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/thudlow_boink/32/320_2.png) [@Thudlow\_Boink](https://boards.straightdope.com/u/Thudlow_Boink)
#### Post date: [January 21, 2024, 11:01pm UTC](https://boards.straightdope.com/t/is-there-a-word-for-this-type-of-brainteaser/996426/15 "2024-01-21T23:01:18Z")

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> [@RickJay](#):
>
> It reminded me of a very famous old riddle; three men check into a hotel.

There has been a [Straight Dope column](https://www.straightdope.com/21342017/riddle-the-3-guys-the-bellhop-and-the-missing-buck) about this one.

> [@RickJay](#):
>
> Is there a word for this type of math puzzle - a puzzle where the arithmetic is actually simple but the wording and closeness of numbers can throw people?
> 
> Know any others?

Not really the same kind of puzzle, I don’t think, but it has in common that it misleads people with irrelevant numbers and irrelevant calculations:

> [@](#):
>
> You’re driving a bus with 10 passengers. At one stop, 2 people get off and 4 people get on. At the next stop, one person gets off and 5 get on. At the next stop, half of the passengers get off and no one gets on. How old is the bus driver?

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### Author: ![Darren\_Garrison](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darren_garrison/32/92_2.png) [@Darren\_Garrison](https://boards.straightdope.com/u/Darren_Garrison)
#### Post date: [January 21, 2024, 11:39pm UTC](https://boards.straightdope.com/t/is-there-a-word-for-this-type-of-brainteaser/996426/16 "2024-01-21T23:39:08Z")

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> [@Thudlow\_Boink](#):
>
> Not really the same kind of puzzle, I don’t think, but it has in common that it misleads people with irrelevant numbers and irrelevant calculations

I once tried combining a word problem and a pun with ChatGPT:

> [@Can we have fun with AI chat?](https://boards.straightdope.com/t/can-we-have-fun-with-ai-chat/994386/20):
>
> Q: A man and his son live 500 miles apart. The man starts driving East to meet his son at 60 miles per hour. At the same time the son starts driving West to meet his father at 80 miles per hour. At the meeting point their cars collide and the father is killed. The son is rushed to the hospital, but the surgeon says “I can’t operate on him, that’s my son!” At the time of the collision, how far had each traveled, and who was the surgeon? A: The answer to the riddle is that the surgeon is his mo…

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### Author: ![Hari\_Seldon](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hari_seldon/32/5173_2.png) [@Hari\_Seldon](https://boards.straightdope.com/u/Hari_Seldon)
#### Post date: [January 22, 2024, 11:18pm UTC](https://boards.straightdope.com/t/is-there-a-word-for-this-type-of-brainteaser/996426/17 "2024-01-22T23:18:04Z")

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As I was going to St. Ives  
I met a man with 7 wives  
And each wife had 7 sacks  
And each sack held 7 cats  
And cat had 7 kits  
Man, wives, sacks, cats, kits  
How many were going to St. Ives?

One. As **I** was going to St. Ives

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### Author: ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)
#### Post date: [January 22, 2024, 11:42pm UTC](https://boards.straightdope.com/t/is-there-a-word-for-this-type-of-brainteaser/996426/18 "2024-01-22T23:42:41Z")

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> [@RickJay](#):
>
> In Riddle 1, the reindeer being sold for $1300 and repurchased for $1400 makes you think that $100 difference matters, but it’s not a relevant number at all.

Sure it matters. Suppose you ignored that intermediate transaction completely: you bought the reindeer for $900 and sold it for $1700. Is that $800 in profit?

No, because you lost $100 in the middle. Subtract that from $800, and you get the correct $700.

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### Author: ![Dr\_Paprika](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr_paprika/32/3042_2.png) [@Dr\_Paprika](https://boards.straightdope.com/u/Dr_Paprika)
#### Post date: [January 23, 2024, 5:01am UTC](https://boards.straightdope.com/t/is-there-a-word-for-this-type-of-brainteaser/996426/19 "2024-01-23T05:01:06Z")

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I don’t know a general term, but one might call them “decoys” since they tend to include extraneous or misleading details that may confuse many.

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### Author: ![Riemann](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/riemann/32/3133_2.png) [@Riemann](https://boards.straightdope.com/u/Riemann)
#### Post date: [January 23, 2024, 5:16am UTC](https://boards.straightdope.com/t/is-there-a-word-for-this-type-of-brainteaser/996426/20 "2024-01-23T05:16:13Z")

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> [@Hari\_Seldon](#):
>
> One. As **I** was going to St. Ives

Perhaps you met at a junction coming from different directions, but all turning toward St Ives. Perhaps you caught up with them while they were having a rest before continuing on their journey to St Ives. And we always need to know how many kittens there are to make sure we don’t lose one.

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