Re: flawed thinking by numbers

[RegretfullyYes]

That thieving bastard of a waiter took it !!

[MrMZaccone]

Adding the tip instead of subtracting it is the problem, 10 - 1 = 9, 9 x 3 = 27, 27 - 2 = 25, the cost of the meal. At no point in time does ADDING the tip to get the number 29 make any sense at all.

[MethanolCH3OH]

I drew the whole thing out in MS Paint, and at no point did any money disappear: each friend has £1 at the end, and the waiter has £27. £27 + £1 × 3 = £30. 

[jonnyqh]

Actually, this is a good example of flawed thinking by numbers. You're not paying £27 + a tip of £2, you're paying a bill of £25 + a tip of £2, which equals the £27 that came out of the pockets of the englishmen.

[SilentMarijuano]

no they paid 25 kept 3 one each and 2 tip which adds up to 30

[MrBigEnchilada]

lol this is dumb. its one thing to add wrong, it's another thing to add the wrong things!!! lol if you add the wrong things you will end up not knowing why did you even went wrong...

one way is to look at the payers' point of view

3 people pay 25, they keep 3 dollars, and $2 tips = $30 in total

another way is to look at the server's point of view

the server got 30 for a $25 bill, returned 3 dollars to the 3 people and then kept 2 for the tips, 25+3 + 2 = 30 in total.

[93tomb]

The £27 includes the tip, and the remaining £3 is what they took back. Had to watch it twice though, thought it was a bit fishy the first time. :)

[asasasarap]

The sum of money they payed is 3x9=27.25 for the food plus two for the tip.Everything is o.k

[Cakerolled]

AIDS AIDS

[Barkspawn]

You added the 2 pound tip twice.

The 9 pound * 3 = 27 is correct and it should end there - the 25 pound meal plus the two pound tip = 27. Then you add in the 2 pounds again to get 29, and continue to work off flawed assumption, and end up asking a meaningless question.

[bobplatypus]

I see what you did there...

[Eagle0600]

The numbers are only wrong because you did the wrong thing with them. They each paid 9, and each kept 1, which totals the 30. Of the 9x3=27 that was paid, 2 is the tip and 25 is the bill. It's all very easy and not confusing at all. You add the tip to the nine dollars, when in fact the tip came FROM the nine dollars, so that's wrong. Your sum of 27+2=29 should therefore be just 27. But you're still missing the money they kept, so make that 27+3=30. Numbers work perfectly when they're used right.

[Dday9876]

This is how a quick change artist works. Heres the answer: Never mix your change or refund with your purchase. Why would anyone Add the 2 on to the 27. You dont add refund money as part of the purchase - you subtract it. The equation will then be set up correctly. The moral is: beware of others to set up a model for you.

[HerrHuffington]

@Dday9876 I've seen videos of people uses this idea to scam retailers out of even 25 bucks at once, you confuse them with the change

[EvilGniusStudios]

I think your question askes how much they each payed. not what the total amount put in was. if they payed evenly they each payed 8.33333333 which X3 = 25 plus the 2 coins they left = 27 plus the 1$ they each took = 30.... you mook,

[EvilGniusStudios]

NUB!!!!!

[capitanmaspingon]

WHY WHY WHY is the amount that they each put in plus the tip should equal 30? that is stupid!!! shouldn't the amount they put in plus the amount they pulled out equal 30 instead? this guy is asking the wrong math questions.

[fhs31053]

they each paid 10 so its 30 10x3=30

and their is a left over five 30-25=5

they each take a dollar so its 2 left 5-3=2

give a 2 dollar tip and its 30 2-2=0

there is no missing bill

[OonslaughtoO]

The easiest way to think about it is that you gave the waiter 30 and he gave you back 5 and you took 3 back.... So, you each paid 9 . Therefore 9x3=27 which is the bill plus the tip plus the 3 you took back... 25+2+3=30...........Which by the way is a horrible tip.

[thatgaybloke]

@OonslaughtoO Hey - we're British, what can I say?

:-)

[Gamer031711]

to make a long explanation short bassically what happened was when they each took back one dollar not all three peopple left tip only two did that one person went home happily with that dollar that made it seem unfair to the other two

[Kieku66]

I pocketed the last one...hehehe

[PlasteredDragon]

There is no missing unit of currency.

The meal was $25 plus a $2 tip, each person paid $10 and got $1 back in change... meaning that each paid $9. $9 x 3 = $27 which is the cost of the meal plus the $2 tip. Nothing is missing at all. You can't add $2 to the $27 total bill because the total bill already contains the $2.

Forgive me for using dollars. I don't know how to make that other symbol on my keyboard.

[TheLastCoolName]

It's not missing.

It's 27 - 2 not 27 + 2, leaving the 25 that they paid and the 5 that they need to split.

[rip256]

Psst. Giving tip?

Much better to use mod.

5 mod 3 = 2 - me takes.

Then we just need to find a way to share 3/3, and that shouldn't be too hard.

[AgnosticAntitheist]

"5 isn't divisible by 3"

Yes it is. The result just isn't a natural number. ;)

[VicariousExtrospect]

*sigh*

Middle school students could tell you you're wrong.

[thatgaybloke]

Bloody hell, I should hope so.

[ratje67]

There never was 30$ on the plate to begin with. No dollar is missing

[WeakAtheist]

You added the tip to the amount that they already paid, 9 euros.

[lesliekwan80]

However it's explained, I know it HAS to do something with God. *smirk*

[Tavereen]

The quantum wave form of the last bill/coin collapsed and it disappeared.

[thatgaybloke]

Or is it just than when they took their eyes of it, it ceased to exist?

[Tavereen]

Or maybe it popped out of existence here and into existence in an alternate universe.

[KingfisnPunk]

@Tavereen lolz

[8DX]

You should've subtracted the £2 tip.

They put in 3 x £10 = £30

They took back 3 x £1 = £3

In other words they paid £27

£25 was the meal + £2 tip.

[DeathWishPictures]

It wasn't a £27 bill it was £25

Plus the £2 is equal to £27

They each put in £10 and took out £1

Meaning they each put in £9

and £9 times 3 is equal to £27 which is the combined amount of the bill and the tip. (£25+£2)

[Icemario87]

This video is so stupid. If they each paid $9. And $9 x 3 is $27. And the waiter got $2. That leaves $25 left over to pay for the meal.

Everything is accounting for. What's the problem?

[UberGodless]

this is how the jews won world wars 1, 2 and 3 now.

[Lagomort]

They each put in 10, but they then each got back 5 which is 1.66666... each. They took the rounded off amount of 1 each leaving 3x.6666666..for the waitress.. which equals 2,,,

add this up and you get 30

[JustGuy17]

The paid 3x9=27 + 2 tip + they have 1 coin left in each pocket - that would be 32 .... wouldn't it ? :-)

The answer of course is that each paid 25/3 which is not equal to 9, as said in the replies bellow.

well known old and funny quiz though - I often use it in social events - but that is all there is to it.

[copred]

A great example of not understanding order of operations... :)

Either way, I've always liked showing this to people to make them scratch their heads.

[M00katron]

they paid the £25 and left £2 tip and took £3 with them. 25+2+3 is £30

the 9x3 cos they paid 10 - 1 is confusing different situations but cleverly. (: ])

[NekoMouser]

Sbvera13 is right. They never paid 27+2, they paid 25+2, which is 27, which is 9 a piece. A classic misdirection puzzle.

But the real question is: Why not just leave the waiter a nice 20% tip (the whole 5 pounds) and go about your day?

2 pounds on 25 is what, 8%? That's just mean.

One should really plan to tip properly or else not go out to eat at all. Next time, these three should pack a sandwich and not waste the waiter's time taking up one of his tables for a mere 8% tip.

[4me2cclearly]

lmao so true;P

[Kunx990]

The problem starts at 0:47 as they but down $10 but picked up $1 each leaving $2 in the tray. This does not mean they payed $9 for the meal.

[hitomaya]

This is one of those sneaky blighter things...

By him saying that they paid only £9 is there to confuse you, you dont know it but your brain is twisting and turning over that 1 fact...

[thatgaybloke]

Yes - it's a "which shell is the pea under". As someone pointed out above, I ran through it a bit slowly and so people had time to catch up. It still puzzles quite a few people even when they've had enough time to think about it.

[yellowlynx]

I realized that too. It is easy to overlook the $25 part which is already paid.

[asphias]

the problem here is that this video gives you too much time to think it over.

if you tell this riddle to your friends and do it quickly, they'll have no idea where the 'missing dollar' went. just because this text goes way to slow you get the time to think about it.

[sbvera13]

The trick is at :59

"27+2=29" this is wrong.

It should be "25+2=27". The author used the TOTAL PAID WITH TIP (aka 27), and added the tip to it again to get 29.

[bostnboy3]

exactly. It is because he is gay so his brain is too small to figure that out

[bostnboy3]

this is the dumbest thing I have ever seen. I guess this is proof that gay people have smaller brains than the rest of us. Seriously, where is the confusion? You just added wrong, there is no missing dollar.

3 people walk in with $10 each ($30 total). pay $27 dollar ($9 each) for the meal and tip, and each leave with a dollar. $27 for the meal + $3 left over =$30.....

if this video puzzled you, beyond why he added the tip twice, and didn't add what the people left with, you may be a retard.

[tehdopefish]

Although I always love seeing homophobia on the internets, please realize that the gay bloke who posted this is in no way the author. This is a very old logic puzzle.

[logoth80]

what you do, is acuse waiter of stealing becouse you cant count ;P

fun trick

[lcharlesjr]

why anyone beyond the age of 5 would be confused about this is troubling...

[grgfrg7]

thats the most retarded video ever and anyone who is wondering about the case of the "missing" dollar is an idiot

[aahdhdg]

They didn't "pay" 9£ each. They each give 10£ and get 1£ back, so they lose a total of 3x9£=27£. That 27£ = the 25£ payment + the 2£ tip.

[charlesandhisworld]

Up the waiters butt.

[dechha1981]

Ah ha! I got it! I did a diagram and then watched the video again to see where the trick was.

They each paid a total of $9, got back $1 each. $9 X 3 = $27 + $3 = $30. That adds up. They paid the 25$ cost of the meal, $2 waiter tip, and $1 each back in their own pockets. 25 + 2 + (3 X 1) = $30. That adds up.

The tricky part was when the video said $9 each PLUS the $2 tip. The $9 each INCLUDES the $2 tip.

[GothicJump]

I still don't get it, They each paid 9$ since they got back 1$ each, so thats 27$ plus the 2$ tip which equals 29$...That's the order which the mathematical fallacy comes in, you can't, redo the order :p.

[angelwhite]

No, they each paid 9£, which is 27£. This 27£ has gone to the 25£ meal and the 2£ tip. The tip is already included in the 27£. The remaining 3£ they got back in the form of 1£ each. The trick comes when they say 27+2=29£ That 2£ is accounted for twice, the difference of 1£ comes because you are accounting for that 2£ out of the 3£ they received back. Namely, he has you counting the wrong thing.

[mbruck77]

It all works out correctly once you adapt the Euro...

[thatgaybloke]

LOL - yes. All we have to do now is convince the Daily Mail readers.

[popeyroach]

this is an easy problem. the problem is that the question has been presented as an unreconcilable equation, when actually the equation is wrong. the bill came to a total of £25. this is the important part. easy person paid £9 bringing the total payment to £27. as the bill was £25 + £2 tip the total paid is £27, which is the total required for the 3 payments of £9. the £30 is just a trick installed at the beginning of the problem to confuse the brain

:)

[Eldrave20]

It's one of the few mathematical anomalies, and it isn't a problem at all if you treat it as an addition/subtraction problem, instead of multiplication/division.

I heard it a bit differently, but the end result is the same. Multiplication/division is the wrong tool for this problem.

[hairyreasoner]

Cheap bastards.

[thatgaybloke]

True - they should be less worried about the "missing" pound and more concerned that the waiter hasn't spit in their coffee.

[flaze3]

The problem starts because you can't divide 5 by 3. In fact each should get 1.6 reccurring or 1.7. If you then do 10 - 1.7 you get 8.3 and 3 x 8.3 is 24.9 which rounded up is of course £25. They would then each have to give about 0.6667 pounds each to make the £2 for the tip. The actual bugger is in reccurring numbers :p (which I'm pretty bad at)

[Mozza314]

Hahaha, seen this one before.

The problem here is that the waiter's tip is part of the 3*$9, so adding the 3*$9 and the $2 tip is meaningless. A net of $27 was spent on the food, $2 was the waiter's tip, and $25 went to the restaurant ($1 is with each of the friends.)

A very tricky one! But as I said I've seen it before.

[thatgaybloke]

It took me a while to work it out the first time I saw it. I wrote it down as an equation to try and figure out what what going on. Working out that 25/3 isn't a whole number was the key bit that made it fall into place for me. It's like that "mathematical proof" that 1=0. It looks impressive until you figure out exactly where the error is. Still, it shows how easily simple numbers can be used to confuse people.

[Roostring]

Trying to pull a fast one!

That's a good one, though.

[cozmikzen]

cheap bastards, should tip $3.75(obviously the brittish equivalent.)

[eequalsfb]

They each paid 9 pounds (27 pounds) and the three remaining pounds are the ones that they got back. The two pounds should not be subtracted from thirty but added to 25 to arrive at the total cost of the meal with tip.

The question is wrong, but a pretty good brain teaser at first.

[QualiaSoup]

Yep, a great example of 'mathematical misdirection'. All down to working out where the 'switch' comes.

[DoctorPlausible]

Yeah, that's a good old one. Well remembered. The thing with maths is that, if you get a wrong answer, it's the *question* that's wrong.

[farvision]

The question was misleading - the addition at 1:01 was inappropriate since 27 is the bill plus tip already. Adding the tip twice isn't right.