Anybody know any good Brain Teasers

A man wanted to get into a members only club so he hid and watched the guard at the door of the club house. The guard said a number to each member as they approached, and the member would respond with a number of their own. If the member responded with the correct number they were let in. If they responded incorrectly they were thrown out. One member came up to the door, the guard said twelve, and the member responded with six and was let in. Another member came to the door, the guard said six and the member responded with three and was let in. Believing he had heard enough, the reject went up to the guard. The guard said ten, and the reject said five, but was not let in. What should the reject have said?
 
Bitchplz said:
A man wanted to get into a members only club so he hid and watched the guard at the door of the club house. The guard said a number to each member as they approached, and the member would respond with a number of their own. If the member responded with the correct number they were let in. If they responded incorrectly they were thrown out. One member came up to the door, the guard said twelve, and the member responded with six and was let in. Another member came to the door, the guard said six and the member responded with three and was let in. Believing he had heard enough, the reject went up to the guard. The guard said ten, and the reject said five, but was not let in. What should the reject have said?


No idea whats the answer
 
The warden of a prison wants to give his 10 prisoners a chance to redeem
themselves. He approaches them one evening when they are all sitting
together and relaxing and tells them the following:

"Tomorrow morning I am going to stand all of you in one line, facing the
same way one behind the other. I will place the shortest in the front and
the tallest at the end of the line so each of you can see all people ahead
of you, but none behind you.

Then, I will proceed to place a hat on each of your heads. Each hat will
either be black or white in colour, but you will not know how many of each
there are (they could be all black, or even all white). Moreover, you will
NOT be able to see the colour of your own hat, but you will be able to see
the colours of all the hats in front of you. So the tallest person will see
9 hats, the next 8 and so on. At this point, I will start from the back (the
tallest) and ask each of you the colour of your own hat. If you are able to
tell me the colour of your hat correctly, you are free to go.
If not, you stay right here in jail.

Let me add, that when you are asked the question, all you can say is "black"
or "white". No other word or signal is allowed. Everyone will be able to
hear your answer, but only the ones behind you will know if it was correct."

So the prisoners' task is to think of a strategy which will allow the
maximum number of them to get out of there. For example, if the 10th person
(the tallest) agrees to call the 9th person's hat colour when his turn
comes, then the 9th person can be assured that he will get out. Of course,
in this case, the 9th person can no longer make such a promise to the 8th
because if the 8th person's hat is a different colour than his own, what
will he call when his turn comes by: his own colour to get out of jail or
the 8th person's colour? So such a strategy will clearly not save more than
5 people (10 tells 9, 8 tells 7 etc.) The question is, can we do better? Is
there a clever strategy that can assuredly get more people out of that
prison in this game?

Hint: YES there is! =)
 
Another one which people usually struggle with

Two ferry boats start at the same instant on opposite sides of the river. One is faster than the other. They cross at a point 720 yards from the left shore on their way to their respective destinations, where each one spends 10 minutes to change passengers before the return trip. They meet again at a point 400 yards from the right shore.

How wide is the river?
 
You may have head this before


Three men go to stay at a hotel and the clerk charges them £30.00 for the room. They split the cost ten dollars each. Later the manager tells the clerk that he overcharged the men and that the actual cost should have been £25.00. He gives the clerk £5.00 and tells him to give it to the men. But he decides to cheat them and pockets £2.00. He then gives each man a pound. Now each man has paid £9.00 to stay in the room and 3 X £9.00 = £27.00. The clerk pocketed £2.00. So where is the other £1.00? :confused:
 
The guy gave himself £2 without people knowing, and then gave everyone £1 including himself so they all thought they had the same - so he actually had £3 - that's where the £1 is, pretty obvious really?

Rich_L said:
If you cut a sandwich in half, how many sandwiches are you left with?
Lol, does 1.9r = 2?
 
carvegio said:
Another one which people usually struggle with

Two ferry boats start at the same instant on opposite sides of the river. One is faster than the other. They cross at a point 720 yards from the left shore on their way to their respective destinations, where each one spends 10 minutes to change passengers before the return trip. They meet again at a point 400 yards from the right shore.

How wide is the river?

I'm tempted to say 1120 yards, but I can't back it up mathematically as I'm sure there's not enough information given.
 
Broon said:
You may have head this before


Three men go to stay at a hotel and the clerk charges them £30.00 for the room. They split the cost ten dollars each. Later the manager tells the clerk that he overcharged the men and that the actual cost should have been £25.00. He gives the clerk £5.00 and tells him to give it to the men. But he decides to cheat them and pockets £2.00. He then gives each man a pound. Now each man has paid £9.00 to stay in the room and 3 X £9.00 = £27.00. The clerk pocketed £2.00. So where is the other £1.00? :confused:

Each man has £1 in his pocket, so that's £3 right there. There's £2 in the clerk's pocket, taking us up to £5. The other £25 is in the till. That makes £30.

The £27 that they have apparently paid already includes the £2 that the clerk has in his pocket.
 
Broon said:
You may have head this before


Three men go to stay at a hotel and the clerk charges them £30.00 for the room. They split the cost ten dollars each. Later the manager tells the clerk that he overcharged the men and that the actual cost should have been £25.00. He gives the clerk £5.00 and tells him to give it to the men. But he decides to cheat them and pockets £2.00. He then gives each man a pound. Now each man has paid £9.00 to stay in the room and 3 X £9.00 = £27.00. The clerk pocketed £2.00. So where is the other £1.00? :confused:

It's lost in currency exchange rates :D
 
Back
Top Bottom