Mathmaticians apply within

[neorichieb1971]

Three sisters shopping for a TV walk past a shop and see a TV on sale for £30!. Bargain they think only £10 each as they always share the cost equally. So in they go to buy the TV, when they get to the assistant to purchase the TV.

He informs them that they are the 1000 customer of the day and qualify for £5 discount!!!. so the sisters all hand the assistant £10 each, the assistant the goes to hand the sisters their £5 pound change, "oh we share things equally" says one sister, so they all agree to take back £1 each and tip the assistant the remaining £2.

However if the sisters all handed over £10 each but received £1 discount, then they only spent £9 each...so in total they spent 3x9 = £27 and tipped the assistant £2, but 27+2 only equals 29??? were did the other £1 go!!!




I know the answer, let some people have a brain tuma over it before some smart alec gives the game away.

[Diabollokus]

oh come on man everyone knows £5 split 3 ways = 1.666 they take one pound from that = 0.666x 3 to give the assistant £2.

There solved.

They spent, 25 got 3 back gave the guy 2. there we go.

[Sly Cherry Chunks]

but 27+2 only equals 29???

This is the part that trips people up. The £2 tip is part of the £27 spent. Adding another £2 onto £27 is nonesense, it should be £27 minus £2 = £25 i.e. - the price of the TV with the £5 discount.

[Ganelon]

Yeah, simple "trying to count the £2 twice/ignoring the full £5 rebate" solution. The challenging part of that question IMO was getting used to the fact that they use £ rather than $....

[neorichieb1971]

Actually your all wrong!

Mathmatics is a perfect science and there is nothing wrong with the wording at all. I have never seen anyone get this right, they always figure something is wrong with the wording.

The only thing wrong with the wording is the last paragraph which adds it up wrong.. but mathmatically its possible to get the full $30.

[Shatterhand]

Actually, Diabollokus answer is right. They paid $30 for a TV that costs $25. They got $3 back, and gave $2 as a tip.

They did not spend $9 each. They spent $8.3333 (25 / 3).

(8.333 * 3) + 3 + 2 = 30


This is a classic problem. I know its solution since I was 12 years old

Have you been reading Malba Tahan books? I know his books are sold internationally, and this problem is available in one of his books (That's why I know the solution of this problem for so long, I read that book for the first time when I was 12 years old )


That's another problem that comes in the same book (I hope I can translate it properly, I won't put it in the book's context):

Two men were travelling in the back of a horse, when they find 3 brothers having an argue. The oldest brother explains what's happening

"You see, my father has passed way, and he left his 35 horses to us. It was his wish that I had half of his horses, the middle son had 1/3 of his horses and the youngest son had 1/9 of his horses. The problem is that we don't know how we can find half or 1/9 of 35 horses!"

One of the 2 friends make a suggestion "Ok, I can help you finding a solution for this... I'll give you our horse, and then everything will be solved"

The brothers look between each other, and accept their horse as a gift, and then wait for the solution.

The man continue: "You see, you should have received half of 35 horses, which means 17,5 horses. Now that you have 36 horses, you should receive 18 horses - You shouldn't complain, as you are getting more horses than you would originally. Your middle brother should have received a third of the horses, which means 11 horses and a little. Now he will get 12 horses - More than he deserved too. And your youngest brother should had 1/9 of 35 horses - less than 4 horses. Now with 36 horses, you will have exactly 4 horses. "

All 3 brothers are very grateful to the man, as with his horse as a gift, they all received more horses than they were supposed to. But then the man speaks again:

"Now wait a minute. 18 horses + 12 horses + 4 horses = 34 horses. Of course, one of them were mine, so I'll get it back. And I think I also deserve the other horse as a gift, as I helped you 3 to solve your problem"

The brothers accept that, and now the 2 friends had 2 horses instead of just one.

How do you explain that? (I hope I could make it clear enough with my english )

[neorichieb1971]

Good one Shatterhand, first person to actually mathmatically work it out.

That riddle about the horses is just nuts.

[shiftace]

So... saying that the sisters spent $25/3 instead of $9 counts as a "mathematical" solution, whereas saying that $27+$2 is the wrong way to calculate spending doesn't count? Eh. As for mathematics being a "perfect science," I don't think it's normally called a science, and it certainly isn't perfect (buzzwords: incompleteness, undecidability, Godel, Chaitin).

And the horses: The given fractions don't sum to 1, and the strangeness follows.

[Shatterhand]

I used to say Math was a perfect science, but then a friend of mine gave me an example that I felt it was just perfect.

Of course, now that I am studying it at a deeper level, I can see even more how its not exactly a "perfect" science

But thats the example my friend gave me (Which he took from his real life )

He had one son. His son gave X amout of trouble when he was a little baby.

5 years later he had two daughters (twins).

If math is perfect, then

1 son = 1*trouble
2 sons = 2*trouble

But that's not what happens, as his twins, being two at the same time, give him more headaches than just his son when he was in the same age.


heh

[Minzoku]

Two men were travelling in the back of a horse

EEW!

when they find 3 brothers having an argue. The oldest brother explains what's happening...

"You see, my father has passed way, and he left his 35 horses to us. It was his wish that I had half of his horses, the middle son had 1/3 of his horses and the youngest son had 1/9 of his horses.

SPOILED:
1/2 + 1/3 + 1/9 = 17/18

And the second half of the problem is just the inverse, 18/17

[Minzoku]

And the horses: The given fractions don't sum to 1, and the strangeness follows.

Ah, whups ...well, I did the math

[Michaelm]

9/18 + 6/18 + 2/18 = 17/18

[Diabollokus]

Good to see you backing me Shatterhand on that one. lol

[neorichieb1971]

Apples are 20cents, oranges are 30 cents, how much are bananas?

[Dartagnan1083]

^impossible to tell. . .no way to solve for unknown variable.
especially with no guide

[neorichieb1971]

Well I posted it on another forum and somebody got the answer.. Somebody gave me the question and I got the answer.. I'm just passing it on.

There is logic in the question, and it has nothing to do with fruit.

[Herr Schatten]

I guess bananas are 30 cents, too?

[neorichieb1971]

Well done.

[ckm]

?! i am crap at maths (in fact i'm just discovering how much moreso that is, as i am taking a class in it justnow for the purposes of learning programming, which doesn't look like its going to happen anyway), but i don't see how that is a problem.

£30.00 for a telly

3 people pay in a tenner each,

then there's a £5.00 discount,

so out of that fiver they take £3.00 back for themselves and each of them takes a pound,

and the two pounds left from the fiver discount, they give to the assistant as the £2.00 tip.

so they paid £30.00

got back 5 quid

and gave two quid of that five quid back as a tip, and kept the other £3.00 of the discount.

30 - 5 = 25

5 = 2 + 3

2 = tip, 3 = keeps, at £1.00 each




what i would say, is this -

i have noticed something very very inexplicably odd that sometimes occurs when cash-counting like in this example, its odd because - as in this example - its easy to figure out what the costs etc are,

yet - there is 'something' there that trips up the calculations on occaision, as can be seen here - the wording of it seems to translate into the actual calculation of the number data, and confuses it.


also, its not maths, its arithmatic / arithmetic / however its spelt-spelled-spleing!

i draw a distinction between counting things that actually exist, like money, and finding formulas to describe things that can or might or do occur.

[ckm]

Two men were travelling in the back of a horse, when they find 3 brothers having an argue. The oldest brother explains what's happening

"You see, my father has passed way, and he left his 35 horses to us. It was his wish that I had half of his horses, the middle son had 1/3 of his horses and the youngest son had 1/9 of his horses. The problem is that we don't know how we can find half or 1/9 of 35 horses!"

One of the 2 friends make a suggestion "Ok, I can help you finding a solution for this... I'll give you our horse, and then everything will be solved"

The brothers look between each other, and accept their horse as a gift, and then wait for the solution.

The man continue: "You see, you should have received half of 35 horses, which means 17,5 horses. Now that you have 36 horses, you should receive 18 horses - You shouldn't complain, as you are getting more horses than you would originally. Your middle brother should have received a third of the horses, which means 11 horses and a little. Now he will get 12 horses - More than he deserved too. And your youngest brother should had 1/9 of 35 horses - less than 4 horses. Now with 36 horses, you will have exactly 4 horses. "

All 3 brothers are very grateful to the man, as with his horse as a gift, they all received more horses than they were supposed to. But then the man speaks again:

"Now wait a minute. 18 horses + 12 horses + 4 horses = 34 horses. Of course, one of them were mine, so I'll get it back. And I think I also deserve the other horse as a gift, as I helped you 3 to solve your problem"

The brothers accept that, and now the 2 friends had 2 horses instead of just one.

How do you explain that? (I hope I could make it clear enough with my english )

35 + 1 = 36

36/2 = 18, for oldest brother

18 left,

1/3 of 36 = 12, for middle bro

18 - 12 = 6, tho' they give 4 to youngest bro, and keep the other two, one of which was already theirs.


see, this is what happens when you start using decimals in real-world things that can never be less than whole.

[99pence]

but 27+2 only equals 29???

This is the part that trips people up. The £2 tip is part of the £27 spent. Adding another £2 onto £27 is nonesense, it should be £27 minus £2 = £25 i.e. - the price of the TV with the £5 discount.

That's exactly right. It's as simple as that. The last part of the question is nonsence.


Why are the bananas 30 cents. How much do they weigh?

[PaCrappa]

Actually your all wrong!

Say what? Everybody that posted before the above quoted declaration got it 100% right. If you don't know nobody that could get it right within about 30 seconds, you need better friends. Furthermore, Diabollukus worked it out just as mathematically as Shatterhand did. Fancy decimals are not needed for something so plain and simple.

99p, nanners is 30 cents because they have the same number of letters in their name as oranges. You might think that's more ridiculously arbitrary than mathematically logical and you wouldn't be the only.

As far as those smelly uncouth horses go, send 'em to the dogfood factory and split the money.

Pa

[Zach Keene]

99p, nanners is 30 cents because they have the same number of letters in their name as oranges. You might think that's more ridiculously arbitrary than mathematically logical and you wouldn't be the only.

Actually I think it works better if you only consider the vowels; then they're all 10c per vowel. Which is of course ludicrous, since everybody knows vowels cost $250.

[PaCrappa]

HAHA! That rules! My mom and grandma both kinda had a crush on Pat Sajak.

Pa

[Dale]

I know allot of riddles that don,t have anything to do with math does anyone care to here them?

[neorichieb1971]

My thread was sitting in the underworld of this forum for far too long, so I resurrected it with a pinch of sarcasm.

Its all good!

[shiftace]

About 10 years ago I saw some stupid/clever numerical argument that Barney is Satan. Anybody else know one?

Ok, here:
Consider the phrase
"Cute Purple Dinosaur,"
and extract the letters
that correspond
to Roman numerals,
counting "u" as "v"
since the Roman
alphabet had no "v."
And the sum is?

[zaphod]

If Apples are 20cents and oranges are 30 cents, how much are bananas?

Corrected.

As written, the question now implies that the information for the solution is there, and this assumption is required to solve the problem.

[99pence]

99p, nanners is 30 cents because they have the same number of letters in their name as oranges.

Right then. I'm off today to get some free figs...

[zaphod]

And now, knowing that all the information is there, we can then take a stab at solving the problem logically. Without assuming all the information is present, we can't get anywhere.

Because the only information we have about the bananas is the word bananas, we can deduce that the words themselves are the key. This follows from the premises that all the information is there, and tat a correct and unique solution exists.

Comparing apples to oranges, we count the same number of consonants(4), and the same number of syllables (2), and a different number of vowels (2 in apples, 3 in oranges). The number of letters are also different. the vowels differ by one number, and this extra vowel bumped the cost up 10 cents. This is the most reasonable conclusion to make, because it is the simplest explanation that fits the facts. therefore we can conclude that consonants are free, and vowels are 10 cents each, and that bananas, which has 3 vowels as well, are also 30 cents. NOw how do we know that we are right logically?

This is the tricky part. We know this, because if something else determined cost (such as number of letters on a logarythmic scale of some sort, and or diffrent weighing of individual letters.) we wouldn't have enough information to deduce the answer. But this contradicts the presupposition implied by the question that there is a unique and reachable answer! so we are LOGICALLY correct in our deductions!