Riddles

[piano man 101]

This is a riddle thread, i say a riddle, first person to get it right says a riddle and so on:


3 men went into a shop and bought a tv costing $30
They each paid $10
When they gave there money the maneger realized it was $5 off day
But he couldnt split $5 cos he had no change
So he gave each man $1 and said it was $3 off day
And he pokected $2

So lets see each man actually paid $9 cos they got $1 back

so $9*3 men = $27 + the $2 the man pocketed = $29

$29? wheres the missing doller?

[piano man 101]

ok i gtg now, so anyone who posts at this thread first gets to start a riddle/.

[leahcim]

There's no missing dollar, just bad maths

The shopkeeper has $27 ($30 less the $3 he gives back) and the men have $1 each = $30.

The $2 you mention the shopkeeper "pocketing" are part of the $27.

Next riddle : There are no uninteresting natural numbers, provide a proof or a counter example.

[piano man 101]

ok u got that right. i mislead you with the maths ok u can say a riddle.

[lau]

I got one. What's lighter than a feather, but to hard to hold.

[leahcim]

I got one. What's lighter than a feather, but to hard to hold.

Your breath

[randmc]

What does man love more than life
Fear more than death or mortal strife
What the poor have, the rich require,
and what contented men desire,
What the miser spends and the spendthrift saves
And all men carry to their graves?

[sharon_f]

Nothing.

[pianohopper]

Next riddle : There are no uninteresting natural numbers, provide a proof or a counter example.

What is a natural number?

wikipedia:    https://en.wikipedia.org/wiki/Natural_number

* There is a natural number 0.
    * Every natural number a has a natural number successor, denoted by S(a).
    * There is no natural number whose successor is 0.
    * Distinct natural numbers have distinct successors: if a ≠ b, then S(a) ≠ S(b).
    * If a property is possessed by 0 and also by the successor of every natural number which possesses it, then it is possessed by all natural numbers. (This postulate ensures that the proof technique of mathematical induction is valid.)

Therefore: 3 is an interesting natural number.  Example:  Three strippers.   
If there were 0 strippers, this would be an uninteresting natural number; however, 0 can be interesting if there are, say: 0 politicians.  That is an interersting idea....

Is this right, or do you mean something else?  I suspect it is a trick question. 

[randmc]

Nothing.

Correct! Here's another one:

You heard me before,
Yet you hear me again,
Then I die,
'Till you call me again.

[Dazzer]

I got one. What's lighter than a feather, but to hard to hold.

well it doesn't say it was hard to hold for a long time. just hard to hold. so i suspect it should be a shadow.

Correct! Here's another one:

You heard me before,
Yet you hear me again,
Then I die,
'Till you call me again.

An echo.

here's a simple one.
Which is heavier. A ton of iron or a ton of steel?

[leahcim]

Is this right, or do you mean something else?  I suspect it is a trick question. 

Sort of.

Let set S, a subset of N be the set of uninteresting natural numbers.
S is well ordered, and thus has a least member, call it n.

n would be the smallest uninteresting number and thus interesting which contradicts the definition of n. QED.

[leahcim]

Which is heavier. A ton of iron or a ton of steel?

Both the same.

[abell88]

Both the same.

Where's  your riddle, Leahcim?

[leahcim]

Where's  your riddle, Leahcim?

That's a conundrum...err, this is more of a problem than a riddle, but :-

(a) Find 3 consecutive integers such that when all possible simple fractions are formed the sum of those 6 fractions is an integer. e.g 4, 5, 6 would be 4/5 + 4/6 + 5/6 + 5/4 + 6/4 + 6/5

(b) If you find one set, can you show whether it's the only one or not?

[lau]

I don't get it, not good at math   

1. What always ends everything?

2. What can you catch, but not throw?

3. Give me food and I live, give me water and I die. What am I?

[randmc]

1. money?!? or maybe its God
2. your breath
3. Fire

[Etude]

I don't get it, not good at math

1. What always ends everything?

2. What can you catch, but not throw?

3. Give me food and I live, give me water and I die. What am I?

1.  "G"
2.  A cold
3.  Not sure... I'll say the same - Fire

[randmc]

1.  "G"
2.  A cold

Ooooooh, I get it, everything. For 2, couldn't you also say breath? Because you can catch your breath but you can't throw it. But youre probably right.

[jas]

I've got one.

You're standing in a room. Two other people are in the room, which has two doors leading out of it. You know that one door is the door to happiness and the other is the door to hell, but not which is which. You also know that one of the people can tell only the truth, the other can tell only lies, but not which is which.

You can ask one question to try to find out which door to go through, remembering that you don't know which person will lie to you. What's the question?

[lostinidlewonder]

Which one isn't the door to hell.

[bearzinthehood]

That's a conundrum...err, this is more of a problem than a riddle, but :-

(a) Find 3 consecutive integers such that when all possible simple fractions are formed the sum of those 6 fractions is an integer. e.g 4, 5, 6 would be 4/5 + 4/6 + 5/6 + 5/4 + 6/4 + 6/5

(b) If you find one set, can you show whether it's the only one or not?

This one doesn't take too much thinking.  1, 2, 3 works.

2/1 + 3/1 + 1/2 + 3/2 + 1/3 + 2/3 = 8

As for part b, clearly those are not the only ones as -3, -2, -1 are also consecutive integers, the sum of whose simple fractions is also 8.

[bearzinthehood]

Which one isn't the door to hell.

This solution does not work, because if you ask the liar he will point to the door to hell, and if you ask the truth teller he will point to the door to happiness.  You only have a 50% chance of succeeding.

Consider instead the following:

Pick a person at random.  Ask this person, "if I asked the other person (the person you're not talking to) to point to the door to happiness, which door would he point to."
- If you ask the liar, he will lie and point to the door to hell.
- If you ask the truth teller he will tell the truth and point to the door to hell.
From this you can deduce that the door to happiness is the opposite of whatever gets pointed to.

[leahcim]

This one doesn't take too much thinking.  1, 2, 3 works.

2/1 + 3/1 + 1/2 + 3/2 + 1/3 + 2/3 = 8

As for part b, clearly those are not the only ones as -3, -2, -1 are also consecutive integers, the sum of whose simple fractions is also 8.

Correct.

A bit more thinking though and you can see that, in general, the numbers are

x-1, x and x+1, so the sum is 6x² / (x²-1)

Since x² and (x²-1) are relatively prime (x²-1) must divide 6, which is only possible in the cases you gave.

[randmc]

I've got one.

You're standing in a room. Two other people are in the room, which has two doors leading out of it. You know that one door is the door to happiness and the other is the door to hell, but not which is which. You also know that one of the people can tell only the truth, the other can tell only lies, but not which is which.

You can ask one question to try to find out which door to go through, remembering that you don't know which person will lie to you. What's the question?

Couldn't you just try out both doors? If you opened up the door to hell and saw that you didn't like it, couldn't you just go back and open the heaven door?

[jas]

Couldn't you just try out both doors? If you opened up the door to hell and saw that you didn't like it, couldn't you just go back and open the heaven door?

No, you couldn't!

Pick a person at random.  Ask this person, "if I asked the other person (the person you're not talking to) to point to the door to happiness, which door would he point to."
- If you ask the liar, he will lie and point to the door to hell.
- If you ask the truth teller he will tell the truth and point to the door to hell.
From this you can deduce that the door to happiness is the opposite of whatever gets pointed to.

That's right. Well done!

Jas

[lau]

you all got it right   

[perfect_pitch]

Is there any way to attach an image you have on your computer hard drive??? I have an interesting Maths Illusion... that might be interesting to see. See if you guys can figure it out. Is there any way to do it without subscribing to those free hsoting sites - I have enough Junk Mail as it is.

[lau]

No, there is no way.

[contrapunctus]

Here is a good one:

Why are French composers so bad?




                                                        (answer below keep scrolling)






























































                                       Because they are French. 

[perfect_pitch]

Someone please shoot Contrapunctus... please - I'll pay them...