In each of the following three configurations of matches, move a single match to form valid equations. The = and + are composed of two matches each.
- \/|+|=\/
- \/|+|=\/|
- \/|+|=|||
Showing posts with label riddle. Show all posts
Showing posts with label riddle. Show all posts
Sunday, August 14, 2011
HOTEL INFINITY
So, an eccentric entrepreneur by the name of Alphonse Null has sent out a press release about his new, mind-blowing hotel: The Hotel Infinity. Null informs the world that this hotel has an infinite number of rooms (specifically, an infinity equal to the cardinality of the integers). A quick tour puts skeptics' claims to rest; as far as anyone can tell, this hotel has infinite rooms. The consequences are mind-boggling, and Null sets up a press conference to answer questions...
"So, Mr. Null, how will patrons get to their room, if their room number has, say, more digits than protons in the universe?"
"The elevators have an ingenious formula device instead of buttons... simply input the formula for your room number, with Ackermann numbers or somesuch... your room formula can be picked up at the front desk. There's not even any need to know what the formula means!"
"How do you produce the power and water for this hotel?"
"I have infinite generators and wells, of course. This IS an infinite hotel, you know! *chuckle*"
"What about costs? How much will it cost to stay here?"
"That's the beauty of it! Since there are as many positive even integers as there are integers, I can change the same price to only every other room and still make the same profit! I could charge only every millionth room... each guest has a one-in-a-million chance of not getting a free room, and I still get paid the same! I love the properties of infinite sets, especially when it comes to profit!"
"But, Mr. Null... I think you've made a severe mistake in your assumptions regarding profit..."
"Oh?"
The reporter then mentioned something which made Mr. Null's face turn white.
"Oh... oh goodness... THIS PRESS CONFERENCE IS OVER!" Then he ran out.
Assuming that everything Null said about the hotel is true: it really is infinite; it really is easy to get to your room; it really can generate infinite power for the guests; the cardinality of the set of multiples of a million, is the same as the cardinality of the integers...
So with what simple assumption did Mr. Null go wrong?
FRYING FOOD
The boiling point of olive oil is higher than the melting point of tin. If Italian skillets are made of tinned copper, how can they be used to fry food in olive oil?
DOMINANT FIFTH
"What's the Dominant Fifth?" asked Dr. Dingo, as his daughter Cicely came in from school.
Cicely blushed. "Just a secret society," she said. "I'm one of the vice-presidents."
"And you're meeting tonight; is that right?"
"How on earth did you know?" ask Cicely.
"You left this lying about. That's no way to keep secrets, my girl." He handed Cicely this paper:
Dominant Fifth
REASM NCNVE OTMLE SEHST TAOEI
"How did you manage to read it?" asked Cicely. "The code is known to only about eight of us."
"Change it," said Dingo. "Any fool can read that."
Where and When is the next meeting scheduled?
Saturday, August 13, 2011
RIVER CROSSING
Two people come to a river. There is a boat, however it can carry one person only. How can they each get to the other side of the river using the boat?
ENVELOPE GAMBLE
I have a distribution over the Reals which you do not know. I choose two numbers from it, and write them inside envelopes. You are given one of the envelopes, and allowed to see the number inside it. Then, you are given the option to switch envelopes once. After you settle on an envelope, you win the amount inside your envelope, and you pay the amount inside the other envelope. Can you win money playing this game, with a strategy independent of my distribution?
Sunday, July 17, 2011
Never ask a womens age :P
In the pub of a quiet little village, the bartender and the local school teacher had the following conversation. The bartender said: "Pastor Petersen was visited by three women today. Can you work out how old they are, if you know that the product of their ages is 2450, and that together they are as old as you are?" After a deep consideration, the teacher said: "No, I can't." Then the bartender said: "Of course you can't, but if I tell you that the oldest woman is older than pastor Petersen, you should be able to work it out." The teacher did. Can you find out how old is pastor Petersen?
Saturday, July 16, 2011
Lateral Thinking Puzzles
1. One day Kerry celebrated her birthday. Two days later her older twin brother, Terry, celebrated his birthday. How come?
2. Deep in the forest was found the body of a man who was wearing only swimming trunks, snorkel and face mask. The nearest lake was 8 miles away and the sea was 100 miles away. How had he died?
3. A blind beggar had a brother who died. What relation was the blind beggar to the brother who died? (Brother is not the answer).
4. A man went to a party and drank some of the punch. He then left early. Everyone else at the party who drank the punch subsequently died of poisoning. Why did the man not die?
5. Several truck drivers at a roadside cafe started to play poker. The pot was large and the game was serious. Suddenly one of the men accused the dealer of cheating. The dealer drew a
knife and, in plain view of all the others, stabbed the man and killed him. The police were called and they interviewed everyone who had been present. But no man was arrested or charged with any offense. Why not?
6. A man was born in Boston, Massachusetts. Both his parents were born in Boston,
Massachusetts. He lived all his life in Boston but he was not a United States citizen. How come?
7. Why is it better to have round manhole covers than square ones?
8. John and David were brothers. John married Jane. David married Diana. The strange thing was, John and Diana shared the same wedding anniversary. David's wedding anniversary was one month before this date and Jane's was one month after it. None of them had ever been divorced or remarried.What was going on here?
9. A truck became wedged under a low bridge. It could not move forward or backward without severely damaging its roof. The truck driver was perplexed until the little girl standing nearby suggested an easy solution. What was it?
10. A man rode into town on Friday. He stayed for three nights and then left on Friday. How come?
11. A woman had two sons who were born on the same hour of the same day of the same year. But they were not twins. How could this be so?
12. When Archduke Ferdinand was shot, in 1914, his attendants could not undo his coat to stem his bleeding wound. Why not?
13. During WWII, why did German soldiers have to shoot the dogs they had carefully trained?
14. Anthony and Cleopatra are lying dead on the floor of a villa in Egypt. Nearby is broken glass. There is no mark on either of their bodies and they were not poisoned. How did they die?
15. A man lives on the tenth floor of a building. Every day, he takes the elevator to the first floor to go shopping. When he returns, he always takes the elevator to the seventh floor and walks the rest of the fight of stairs to his apartment in the tenth floor. Why does he do this?
16. One night during the Second World War, an allied bomber was on a mission over Germany. The plane was in perfect condition and everything on it worked properly. When it had reached its target, the pilot ordered the bomb doors open. They opened. He then ordered the bombs released. The were released. But the bombs did not fall from the plane. Why should this be so?
17. Five pieces of coal, a carrot, and a scarf are lying on the lawn. Nobody put them on the lawn, but there is a perfectly logical reason for them being there. What is it?
18. There were two Americans waiting at the entrance to the British Museum. One of them was the father of the other one's son. How could this be so?
19. Not far from Madrid, there is a large wooden barn. The barn is completely empty except for a dead man hanging from the central rafter. The rope around his neck is ten feet long and his feet are three feet from the ground. The nearest wall is 20 feet away. It is not possible to climb up the walls or along rafters, yet he hanged himself. How did he manage it?
20. What happened in the second half of the 20th century and will not happen again for another 4000 years?
21. Why did an old lady always answer the door wearing her hat and coat?
22. Many more children are involved as pedestrians in road accidents than might be expected from their numbers and road use. An expert on road accidents has put forward an ingenious theory to account for this. What do you think the theory might be?
23. Two drivers drove slowly and safely in the correct direction down a wide road before coming to a stop in front of a red stop light. A nearby police officer immediately arrested one of the drivers and let the other one driver off. The police officer had never seen or heard either driver before. Neither driver had a criminal record. They were both fully dressed and no one had been drinking. Both cars were in excellent roadworthy condition and had not been stolen. The arrested driver was charged and convicted. Of what?
24. A man locks his keys inside his car and is unable to get them out despite trying for an hour. A police officer comes along and offers to help. He discovers that the back door of the car is unlocked and he consequently recovers the keys. The man thanks him, but when the officer departs the man locks the back door, leaving the keys inside. Why?
25. A man wanted to construct an important building and he received tenders from a hundred builders, who each presented their qualifications and claimed to be the best builder around. How did he chose between them?
26. A very unlucky gambler had lost all his money . His friends organized a raffle, rigged so he would be sure to win. Knowing the ticket number he held, they filled a hat with tickets bearing the same number. The asked him to draw the winning number. "Well," they asked him, "who won?" "Not me, anyway," he replied sadly. What had happened?
27. A man is lying dead in a field. Next to him there is an unopened package. There is no other creature in the field. How did he die?
2. Deep in the forest was found the body of a man who was wearing only swimming trunks, snorkel and face mask. The nearest lake was 8 miles away and the sea was 100 miles away. How had he died?
3. A blind beggar had a brother who died. What relation was the blind beggar to the brother who died? (Brother is not the answer).
4. A man went to a party and drank some of the punch. He then left early. Everyone else at the party who drank the punch subsequently died of poisoning. Why did the man not die?
5. Several truck drivers at a roadside cafe started to play poker. The pot was large and the game was serious. Suddenly one of the men accused the dealer of cheating. The dealer drew a
knife and, in plain view of all the others, stabbed the man and killed him. The police were called and they interviewed everyone who had been present. But no man was arrested or charged with any offense. Why not?
6. A man was born in Boston, Massachusetts. Both his parents were born in Boston,
Massachusetts. He lived all his life in Boston but he was not a United States citizen. How come?
7. Why is it better to have round manhole covers than square ones?
8. John and David were brothers. John married Jane. David married Diana. The strange thing was, John and Diana shared the same wedding anniversary. David's wedding anniversary was one month before this date and Jane's was one month after it. None of them had ever been divorced or remarried.What was going on here?
9. A truck became wedged under a low bridge. It could not move forward or backward without severely damaging its roof. The truck driver was perplexed until the little girl standing nearby suggested an easy solution. What was it?
10. A man rode into town on Friday. He stayed for three nights and then left on Friday. How come?
11. A woman had two sons who were born on the same hour of the same day of the same year. But they were not twins. How could this be so?
12. When Archduke Ferdinand was shot, in 1914, his attendants could not undo his coat to stem his bleeding wound. Why not?
13. During WWII, why did German soldiers have to shoot the dogs they had carefully trained?
14. Anthony and Cleopatra are lying dead on the floor of a villa in Egypt. Nearby is broken glass. There is no mark on either of their bodies and they were not poisoned. How did they die?
15. A man lives on the tenth floor of a building. Every day, he takes the elevator to the first floor to go shopping. When he returns, he always takes the elevator to the seventh floor and walks the rest of the fight of stairs to his apartment in the tenth floor. Why does he do this?
16. One night during the Second World War, an allied bomber was on a mission over Germany. The plane was in perfect condition and everything on it worked properly. When it had reached its target, the pilot ordered the bomb doors open. They opened. He then ordered the bombs released. The were released. But the bombs did not fall from the plane. Why should this be so?
17. Five pieces of coal, a carrot, and a scarf are lying on the lawn. Nobody put them on the lawn, but there is a perfectly logical reason for them being there. What is it?
18. There were two Americans waiting at the entrance to the British Museum. One of them was the father of the other one's son. How could this be so?
19. Not far from Madrid, there is a large wooden barn. The barn is completely empty except for a dead man hanging from the central rafter. The rope around his neck is ten feet long and his feet are three feet from the ground. The nearest wall is 20 feet away. It is not possible to climb up the walls or along rafters, yet he hanged himself. How did he manage it?
20. What happened in the second half of the 20th century and will not happen again for another 4000 years?
21. Why did an old lady always answer the door wearing her hat and coat?
22. Many more children are involved as pedestrians in road accidents than might be expected from their numbers and road use. An expert on road accidents has put forward an ingenious theory to account for this. What do you think the theory might be?
23. Two drivers drove slowly and safely in the correct direction down a wide road before coming to a stop in front of a red stop light. A nearby police officer immediately arrested one of the drivers and let the other one driver off. The police officer had never seen or heard either driver before. Neither driver had a criminal record. They were both fully dressed and no one had been drinking. Both cars were in excellent roadworthy condition and had not been stolen. The arrested driver was charged and convicted. Of what?
24. A man locks his keys inside his car and is unable to get them out despite trying for an hour. A police officer comes along and offers to help. He discovers that the back door of the car is unlocked and he consequently recovers the keys. The man thanks him, but when the officer departs the man locks the back door, leaving the keys inside. Why?
25. A man wanted to construct an important building and he received tenders from a hundred builders, who each presented their qualifications and claimed to be the best builder around. How did he chose between them?
26. A very unlucky gambler had lost all his money . His friends organized a raffle, rigged so he would be sure to win. Knowing the ticket number he held, they filled a hat with tickets bearing the same number. The asked him to draw the winning number. "Well," they asked him, "who won?" "Not me, anyway," he replied sadly. What had happened?
27. A man is lying dead in a field. Next to him there is an unopened package. There is no other creature in the field. How did he die?
Sunday, July 10, 2011
HUMMINGBIRD
One train leaves Los Angeles at 15mph heading for New York. Another train leaves from New York at 20mph heading for Los Angeles on the same track. The distance between LA and NY is about 5000 miles. If a bird, flying at 25mph, leaves from Los Angeles at the same time as the train and flies back and forth between the two trains until they collide, how far will the bird have traveled?
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