The riddles and trivia thread

[Threeme2189]

I noticed that a lot of forum members like riddles, questions and other challenges. So I thought, why not make a thread dedicated to boggling the mind?

The rules are simple:
Somebody posts a riddle, trivia question, or something similar, and the 1st one to answer correctly (after the person who asked confirms the answer is right) gets to ask his question, etc'.

For example, I'll post the 1st question, and after somebody answers right and I confirm it's the right answer, that person gets to ask his/her question, and so on.

The questions have to be solvable, without guessing. No "pick a number" or "guess my nephews birthday" or anything that can only be guessed.

I'll start:

How can you split a regular round cake into 14 pieces with 4 straight knife cuts? The pieces don't have to be of even volume or shape, and you can not fold or stack the cake in any way.
Good luck

 

[Threeme2189]

Nobody?

[Bruce909]

I'm still trying to figure out which tool I will use.

Bruce

[Carlos]

The pieces can me moved after been cut or the cuts must be made with the cake in its original position?

[Threeme2189]

The pieces can me moved after been cut or the cuts must be made with the cake in its original position?

No they can't be moved.

[cerbera147]

Your first three cuts form a triangle in the middle, which is surrounded by pieces on each corner and each side. That makes seven pieces.

Then cut the cake in half lengthwise

[Pacu]

I think that question was one part of the Kobayashi Maru.

[Threeme2189]

Your first three cuts form a triangle in the middle, which is surrounded by pieces on each corner and each side. That makes seven pieces.

Then cut the cake in half lengthwise

Very good

Your turn.

[enki_ck]

Like this, 3 cuts on top and one through the middle.

Edit: Dang, already solved. That's for trying to ply with Paint.

[enki_ck]

Great idea BTW, always like those games. I ended one of those after 489 replies by asking how many individual parts a LM Wave has. No answer for 5 weeks. 

[cerbera147]

A nice easy one 

A man was found dead in his house. He was slumped over his desk and a gun was in his hand. There was a cassette recorder on his desk. When the police entered the room and pressed the play button on the tape recorder they heard: "I can't go on. I have nothing to live for." Then there was the sound of a gunshot. How did the detective immediately know that the man had been murdered and it wasn't a suicide?

[enki_ck]

He didn't have to rewinde the tape.

[cerbera147]

He didn't have to rewinde the tape.

 

Your turn

[enki_ck]

Ok, a harder one this time.

Why do clothes get darker when they're wet, though the water is clear?

[tattoosteve99]

Because water fills in the gaps of the cloth. Making light pass through more. Less light reflected back to your eye darker it is.

[Threeme2189]

That's a good question!
Even though it won't help me get the next question, I think Steve is right

[enki_ck]

steves turn

[Threeme2189]

Great idea BTW, always like those games. I ended one of those after 489 replies by asking how many individual parts a LM Wave has. No answer for 5 weeks. 

By the way i counted 30 parts, not including the bits, taking apart the scissors or the locks..

[enki_ck]

Great idea BTW, always like those games. I ended one of those after 489 replies by asking how many individual parts a LM Wave has. No answer for 5 weeks. 

By the way i counted 30 parts, not including the bits, taking apart the scissors or the locks..

The problem was I asked for those. And washers, levers, rivets, ...

[Threeme2189]

37 I think.

[Threeme2189]

OK, I'm setting a 2 day time limit.

Here's the next riddle:

There are 50 coins randomly spread on a table. Each of them has a red side and a blue side.
You know that 10 of them have the blue side facing up and the rest have the red side facing up.
You need to divide all of the coins into two groups, and each group has to have the same number of coins with the blue side facing upwards. The groups don't have to have the same number of coins.
The only problem is that you are totally color blind.
How do you do it?

 

[tattoosteve99]

How do you know they are red and blue if your color blind.

[Threeme2189]

How do you know they are red and blue if your color blind.

Tim Leatherman told you. He would never lie

[Carlos]

About the coins... I reduced the scale of the problem to exhaust all combinations, so I translated that to 10 bits, with 8 random 1s and 2 0s. I found out swapping the first two bits would level the number the 0s in those 2 regarding the number in the other 8.

in the following table each line contains only 2 0s.
00|11111111
01|01111111
10|01111111
11|00111111

then swap 1st 2 bits and leave others as is, it results:
11|11111111
10|01111111
01|01111111
00|00111111

both groups always contains the same number of 0s.


So answering to the original question: take a random group of any 10 coins, and flip them. The number of blue coins in that 10-element set will be the same as the number of blue coins on the other 40-element set. I think that's it.

[Threeme2189]

About the coins... I reduced the scale of the problem to exhaust all combinations, so I translated that to 10 bits, with 8 random 1s and 2 0s. I found out swapping the first two bits would level the number the 0s in those 2 regarding the number in the other 8.

in the following table each line contains only 2 0s.
00|11111111
01|01111111
10|01111111
11|00111111

then swap 1st 2 bits and leave others as is, it results:
11|11111111
10|01111111
01|01111111
00|00111111

both groups always contains the same number of 0s.


So answering to the original question: take a random group of any 10 coins, and flip them. The number of blue coins in that 10-element set will be the same as the number of blue coins on the other 40-element set. I think that's it.

Even though I messed up the number of coins (it's supposed to be 100), the riddle still has the same answer and you got it right

Your turn.

[Carlos]

I'm leaving now -- as we speak -- and will be offline until friday, so it's better to pass my riddle turn. I'll propose a riddle if I'll have that chance again, though.

[enki_ck]

Ok, then I'll jump in with one summer heat inspired question.

If normal human temperature is 36.5C/97.7F, why do we feel so hot when it's 36C/97F outside?

[Threeme2189]

Ok, then I'll jump in with one summer heat inspired question.

If normal human temperature is 36.5C/97.7F, why do we feel so hot when it's 36C/97F outside?

Because our bodies create heat, and they need to cool down in order to stay on 36.5C.
So the outside of our bodies (extremities and skin) is cooler than our core temperature, and that's why 36.5C is so friggin hot!
I think.

[enki_ck]

But we could skip the wait for confirmation part. Just post your answer and next question in the same post.

[Threeme2189]

But we could skip the wait for confirmation part. Just post your answer and next question in the same post.

Aww heck, lets do that

Riddle me this:

You have a set of scales and 10 identical coin, except that one of them is a different weight.
How can you find the different coin with just three weighs on the scale?