Brain Teasers

[Laba-X]

1. A man is walking to the town of Ipswich. He comes to a fork in the road, with the two branches leading in two different directions. He knows that one of them goes to Ipswich, but he doesn't know which one. He also knows that in the house right beside the fork in the road there are two brothers, identical twins, both of whom know the road to Ipswich. He knows that one brother always lies and the other always tells the truth, but he cannot tell them apart. What single question can he ask to whoever answers his knock on the door which will indicate to him the correct road to Ipswich?

 

2. Three men are placed directly in line facing a wall. The man at the back can see the two in front of him, the man in the middle can see the man immediately in front, and the man at the front can see only the wall. Each man has a hat on his head, taken from a supply of three black hats and two white hats (the men know this). They are told to remain in line silently until one of them can guess the colour of the hat on his head. That man gets a large cash prize. After five minutes of standing in line, the man facing the wall (at the front of the line) correctly identifies the colour of the hat on his head. What colour must it be? How did he arrive at the correct conclusion? Note that he did not guess.

[Mtoto Wa Geti Kali]

#1:

 

"If I asked your brother what road leads to Ipswich? Which road will he point at?"

[Mtoto Wa Geti Kali]

For #1:

 

The question you ask any of the brothers is:

 

"If I ask Your Brother What Road Leads To Ipswich,What Road Will He Point At?"

 

The Road he points at, you take the opposite one.

[Mtoto Wa Geti Kali]

For #1:

 

The question you ask any of the brothers is:

 

"If I ask Your Brother What Road Leads To Ipswich,What Road Will He Point At?"

 

The Road he points at, you take the opposite one.

[Wisdom_Seeker]

Originally posted by Da Scarecrow:

For #1:

 

The question you ask any of the brothers is:

 

"If I ask Your Brother What Road Leads To Ipswich,What Road Will He Point At?"

 

The Road he points at, you take the opposite one.

What if you were asking the brother that tells the truth. Remember you can’t tell them apart.

 

This is hard i need to think about it

[Wisdom_Seeker]

Originally posted by Laba_Xiniinyood:

1. A man is walking to the town of Ipswich. He comes to a fork in the road, with the two branches leading in two different directions. He knows that one of them goes to Ipswich, but he doesn't know which one. He also knows that in the house right beside the fork in the road there are two brothers, identical twins, both of whom know the road to Ipswich. He knows that one brother always lies and the other always tells the truth, but he cannot tell them apart. What single question can he ask to whoever answers his knock on the door which will indicate to him the correct road to Ipswich?

Do you have a twin? The one that tells the truth will say yes, the other one will say no.

 

 

Am i right...I am soo smart.

[Cara.]

Mystic, think.

 

The answer to the second one: the man is wearing a black hat. He reasoned that the first man can see both men in front of him. If they were both wearing white hats, that man would've guessed right away that he must be wearing a black hat. Since he doesn't call out right away, the men in front of him must be wearing two black hats or one is wearing a black hat and the other is wearing a white hat. The middle man would also know this. If he can see that the man in front of him is wearing a white hat, he would know that he himself must be wearing a black hat. Since he says nothing, he must be looking at a black hat (and isn't sure which one he's wearing himself).

 

I hope that made sense.

[Intuition]

I think the second is a trick question and that the first guy knew the color of his hat because he picked it himself. It didn't rule out the possiblity that he picked it himself.

The first one just makes me comfused. Maybe ask both of them "take me to Epswich" and they'll take you to both, you never mentioned a time restriction so if its not the first place they take you its the other one :confused:

[Mtoto Wa Geti Kali]

Originally posted by Laba_Xiniinyood:

[QB] 1. A man is walking to the town of Ipswich. He comes to a fork in the road, with the two branches leading in two different directions. He knows that one of them goes to Ipswich, but he doesn't know which one. He also knows that in the house right beside the fork in the road there are two brothers, identical twins, both of whom know the road to Ipswich. He knows that one brother always lies and the other always tells the truth, but he cannot tell them apart. What single question can he ask to whoever answers his knock on the door which will indicate to him the correct road to Ipswich?

 

Can U Confirm! I'm 99.9% sure I got #1 right

[A.J.]

Mystic,

 

your answer cant be right because if you ask the person opening the door- Do you have a twin? whatever answer he gives (yes/no) you still have to ask another question about the direction to Ipswich. and remember you're only allowed one question so your answer cant be wrong,

 

I cant guess either but i think it is time that Laba_Xiniinyood give us the answer.

[Qandalawi]

I think Da_Scarecrow got it right number 1

 

But IM confussed about the second question, it wasn't very clear.

[Intuition]

And why can't my answer be right?!!!!

[Centurion]

The answer to the second one: the man is wearing a black hat. He reasoned that the first man can see both men in front of him. If they were both wearing white hats, that man would've guessed right away that he must be wearing a black hat. Since he doesn't call out right away, the men in front of him must be wearing two black hats or one is wearing a black hat and the other is wearing a white hat. The middle man would also know this. If he can see that the man in front of him is wearing a white hat, he would know that he himself must be wearing a black hat. Since he says nothing, he must be looking at a black hat (and isn't sure which one he's wearing himself).

well done Cara , unless i'm very much mistaken you've solved it.

[Som@li]

Da Scarecrow got the first one, I think.

 

 

For the second one, the man at the back of the line knows he got a black hat,by seeing the two guys in front of him got the ONLY two white hats.

 

The man facing the wall by hearing this( which is not ruled out) can come to a conclusion that he got a white hat. easy!