Some Riddles!

m0ei

Well why not post here some riddles you know.

I heard of this riddle before, just checked it out today. Took like 10 min to solve it on a piece of paper.

ALBERT EINSTEIN'S RIDDLE

1. In a street there are five houses, painted five different colours.
2. In each house lives a person of different nationality
3. These five homeowners each drink a different kind of beverage, smoke different brand of cigar and keep a different pet.

THE QUESTION: WHO OWNS THE FISH?

HINTS

1. The Brit lives in a red house.
2. The Swede keeps dogs as pets.
3. The Dane drinks tea.
4. The Green house is next to, and on the left of the White house.
5. The owner of the Green house drinks coffee.
6. The person who smokes Pall Mall rears birds.
7. The owner of the Yellow house smokes Dunhill.
8. The man living in the centre house drinks milk.
9. The Norwegian lives in the first house.
10. The man who smokes Blends lives next to the one who keeps cats.
11. The man who keeps horses lives next to the man who smokes Dunhill.
12. The man who smokes Blue Master drinks beer.
13. The German smokes Prince.
14. The Norwegian lives next to the blue house.
15. The man who smokes Blends has a neighbour who drinks water.

ALBERT EINSTEIN WROTE THIS RIDDLE EARLY DURING THE 19th CENTURY. HE SAID THAT 98% OF THE WORLD POPULATION WOULD NOT BE ABLE TO SOLVE IT. (Not true, It's not that hard.)

Georges

- How to put an elephant in the fridge in 3 moves ?
- How to put a giraffe in the fridge with 4 moves ?
- How to put 5 elephants in a mini cooper ?
- How to put 10 elephants in a Cadillac ?
- How do you know that 10 elephants went out to a pub ?

xterm

- In a prison
- There's 100 inmates
- A warden
- A room with a lighswitch (On/Off) and a light bulb.
- The warden gathers the inmates and says:
- "I will set you all free, if you can beat my game"
- Game Rules:
- After the gathering, no in-mate can speak, see or hear other in-mate until the game is done.
- Warden will bring each on of the in-mates at a time and put him in the room for a bit then send him back to his cell.
- Warden can bring the same in-mate in the room many number of times.
- The game ends, when one of the in-mates gets out of the room and tells the warden, "By now, everyone of us has entered this room, atleast one time".
- The game may take centuries to complete

What strategy do the in-mates devise, before being secluded from one another until the game ends?

mezin

@m0ei the riddle isn't even einstein's to begin with and it has been done a lot
@geroges ... lol

@xterm, they choose a prisoner to be the counter and when a prisoner enters the room for the first time and the light switch is off he turns it on, when the counter enters he turns it off, if a prisoner was already there he leaves it untouched and if he wasn't but the light is on he leaves it on for the counter to turn off .. once the counter has turned it off 99 times he knows everyone has been there at least once

Joe

mezin wrote@m0ei the riddle isn't even einstein's to begin with

Some people claim it was.

cullinan86

Good work Mezin, I had almost the same thought but you figured all its aspects.

xterm

mezin wrote@m0ei the riddle isn't even einstein's to begin with and it has been done a lot
@geroges ... lol

@xterm, they choose a prisoner to be the counter and when a prisoner enters the room for the first time and the light switch is off he turns it on, when the counter enters he turns it off, if a prisoner was already there he leaves it untouched and if he wasn't but the light is on he leaves it on for the counter to turn off .. once the counter has turned it off 99 times he knows everyone has been there at least once

Good job mezin.

babum

xterm wrote- In a prison
- There's 100 inmates
- A warden
- A room with a lighswitch (On/Off) and a light bulb.
- The warden gathers the inmates and says:
- "I will set you all free, if you can beat my game"
- Game Rules:
- After the gathering, no in-mate can speak, see or hear other in-mate until the game is done.
- Warden will bring each on of the in-mates at a time and put him in the room for a bit then send him back to his cell.
- Warden can bring the same in-mate in the room many number of times.
- The game ends, when one of the in-mates gets out of the room and tells the warden, "By now, everyone of us has entered this room, atleast one time".
- The game may take centuries to complete

What strategy do the in-mates devise, before being secluded from one another until the game ends?

Though solved, perhaps the inmate could just say "By now, everyone of us has entered this room, atleast one time".

There is no clause that states that all inmates need to go through for the game to be finished. The only requirement is that the inmate say the mentioned phrase.

on another hand, if they were to play along and let everyone go in, if the Warden is the one making the choices then most probably he would never allow the 100 inmates to go in, no point in doing anything.

mesa177

Georges wrote- How to put an elephant in the fridge in 3 moves ?
- How to put a giraffe in the fridge with 4 moves ?
- How to put 5 elephants in a mini cooper ?
- How to put 10 elephants in a Cadillac ?
- How do you know that 10 elephants went out to a pub ?

- Chop off head, upper body limbs and torso, and lower body torso with feet, then stick into butcher's meat freezer
- Similar to upper solution, only sectioning occurs as head, neck, upper body limbs and torso, and lower body torso with feet
- Set 5 elephants free in a zoo and dedicate it to "Mini Cooper"
- Similar to upper solution, but this time name the zoo "Cadillac"
- You get 10 texts from 10 different drunk men saying that they just met the most beautiful woman they ever saw :P

m0ei wroteWell why not post here some riddles you know.

I heard of this riddle before, just checked it out today. Took like 10 min to solve it on a piece of paper.

ALBERT EINSTEIN'S RIDDLE

1. In a street there are five houses, painted five different colours.
2. In each house lives a person of different nationality
3. These five homeowners each drink a different kind of beverage, smoke different brand of cigar and keep a different pet.

THE QUESTION: WHO OWNS THE FISH?

HINTS

1. The Brit lives in a red house.
2. The Swede keeps dogs as pets.
3. The Dane drinks tea.
4. The Green house is next to, and on the left of the White house.
5. The owner of the Green house drinks coffee.
6. The person who smokes Pall Mall rears birds.
7. The owner of the Yellow house smokes Dunhill.
8. The man living in the centre house drinks milk.
9. The Norwegian lives in the first house.
10. The man who smokes Blends lives next to the one who keeps cats.
11. The man who keeps horses lives next to the man who smokes Dunhill.
12. The man who smokes Blue Master drinks beer.
13. The German smokes Prince.
14. The Norwegian lives next to the blue house.
15. The man who smokes Blends has a neighbour who drinks water.

ALBERT EINSTEIN WROTE THIS RIDDLE EARLY DURING THE 19th CENTURY. HE SAID THAT 98% OF THE WORLD POPULATION WOULD NOT BE ABLE TO SOLVE IT. (Not true, It's not that hard.)

Déjà vu...

Ironically, the past phrase reminds me of this game, seeing that when I reached level 14, I thought it was the username/password for the next level but instead I got stuck. It still bugs me...

I also miss this post.

xterm

babum wroteThough solved, perhaps the inmate could just say "By now, everyone of us has entered this room, atleast one time".

There is no clause that states that all inmates need to go through for the game to be finished. The only requirement is that the inmate say the mentioned phrase.

It wasn't word play, but if it makes you feel better, you can add the aforementioned to the requirements.

on another hand, if they were to play along and let everyone go in, if the Warden is the one making the choices then most probably he would never allow the 100 inmates to go in, no point in doing anything.

Again, this is a riddle, it is granted that the warden is atleast honest about his 'game'. I did mention atleast, that the game could take centuries to complete, just to hint that the warden could bring in the same inmate into the room thousands if not millions of time.

Nemesis-301

its not really a riddle, more of a paradox. But it got me to really think about time travel:

What happens if someone goes back in time and kills their own grandmother, before his grandmother gives birth to his mother? what happens to him?
now, you're going to think that, well he wouldn't exist, right? well, if he doesn't exist, how can he go back in time and kill his grandmother?

yasamoka

Nemesis-301 wroteits not really a riddle, more of a paradox. But it got me to really think about time travel:

What happens if someone goes back in time and kills their own grandmother, before his grandmother gives birth to his mother? what happens to him?
now, you're going to think that, well he wouldn't exist, right? well, if he doesn't exist, how can he go back in time and kill his grandmother?

Time travel would directly imply that there is no causation. This is why physicists have trouble with the concept of time travel.

samer

This one was asked to my brother during his interview with a big financial institution for a trading position.
There is a round table. You are playing against an opponent and are provided with identical glasses. When his turn comes up, a player will place one glass on the table. The players will continue alternating turns until the table is full. The player whose turn comes up and can't place a glass on the table loses.

Now the question: if you are given the choice, would you choose to be the first to put a glass on the table? If so, where would you place it?

Joe

@samer:
I'd go first and put the first glass at the center. Next, I'd wait for his move and place a glass at the symmetrical opposite of his each time. This would work because:

- glasses are identical.
- for each A on the table, the symmetrical opposite (with respect to the center) B is unique and sym(A) = B implies sym(B) = A. (does this property have a name?)

Also, now that I think of it, by the above reasoning, you could argue that there's a finite amount of glasses you can fit on the table and this number is odd ((every point + its opposite) + the center). That proves that as long as you go first, no matter where you put the glasses, you'll win.

Beej

@ Samer, it has the same basic concept of tic-tac-toe.

MSD

You are a secret agent, your mission is to blow up an arms factory. For reasons we won't get into, you plan to do it old school, using fuses and gun powder, not timers and C4 and that stuff. You have 2 fuses, each burn from end to end in exactly 30 minutes. The fuse does not have a uniform distribution of gun powder, in other words, it does not burn in a constant speed, for ex: 99% of the fuse could take 1 minute to burn and the remaining 1% of its length 29 minutes. You estimate it takes you 45 minutes to make it out of the factory and need to use the 2 fuses you got to build a time bomb that will explode after 45 minutes from lighting the fuse(s).

EDIT

To avoid confusion, let me correct my scenario:
All you care about is creating a timer, forget about how the fuse is attached (or not) to the bomb

m-sabra

Georges wrote- How to put an elephant in the fridge in 3 moves ?
- How to put a giraffe in the fridge with 4 moves ?
- How to put 5 elephants in a mini cooper ?
- How to put 10 elephants in a Cadillac ?
- How do you know that 10 elephants went out to a pub ?

-1- open the fridge ; 2- put the elephant ; 3- close the fridge.
-1- open the fridge ; 2-remove the elephant from there :P ; 3-put the giraffe ; 4-close the fridge
-2 in the front seats and 3 in the backseats
-sell the Cadillac,buy 2 mini coopers put 5 in each mini the way i mentioned above (don't know if it's still legit :P)
-you see 2 mini coopers parking outside.

Keep it simple ;)

Joe

@MSD: Can you "waste" a third fuse to measure 15 mins by lighting it simultaneously from both sides?

m-sabra

MSD wroteYou are a secret agent, your mission is to blow up an arms factory. For reasons we won't get into, you plan to do it old school, using fuses and gun powder, not timers and C4 and that stuff. You have 2 fuses, each burn from end to end in exactly 30 minutes. The fuse does not have a uniform distribution of gun powder, in other words, it does not burn in a constant speed, for ex: 99% of the fuse could take 1 minute to burn and the remaining 1% of its length 29 minutes. You estimate it takes you 45 minutes to make it out of the factory and need to use the 2 fuses you got to build a time bomb that will explode after 45 minutes from lighting the fuse(s).

ok tie the first fuse by half (put both ends of the fuse together and twist it together so it become a full fuse with half the size of a normal fuse) attach it to the other fuse (keep this one normal) and light it.the unmodified fuse will take 30 minutes, the twisted fuse will start burning both layers that are twisted together so until it finish burning it will take 15 minutes so 45 min in total.

MSD

m.sabra wrote
MSD wroteYou are a secret agent, your mission is to blow up an arms factory. For reasons we won't get into, you plan to do it old school, using fuses and gun powder, not timers and C4 and that stuff. You have 2 fuses, each burn from end to end in exactly 30 minutes. The fuse does not have a uniform distribution of gun powder, in other words, it does not burn in a constant speed, for ex: 99% of the fuse could take 1 minute to burn and the remaining 1% of its length 29 minutes. You estimate it takes you 45 minutes to make it out of the factory and need to use the 2 fuses you got to build a time bomb that will explode after 45 minutes from lighting the fuse(s).
ok tie the first fuse by half (put both ends of the fuse together and twist it together so it become a full fuse with half the size of a normal fuse) attach it to the other fuse (keep this one normal) and light it.the unmodified fuse will take 30 minutes, the twisted fuse will start burning both layers that are twisted together so until it finish burning it will take 15 minutes so 45 min in total.

You don't really need to twisted into a fuse, All you need is to make a loop:

-- FUSE 1
-- FUSE 2
become --O
You light it from the left and when the flame reaches the point of intersection the second fuse would light from both ends.