A man was killed in his office. At the time of murder there were only four people in the office: Bill, Tom, Harry and Mike. When police interrogated them, they gave the following statements. Bill: “Tom did it.” Tom: “Bill did it.” Harry: “Tom’s telling the truth.” Mike: “Harry’s not lying.” After analysis, the police found out that only one person was telling the truth and the rest were lying. Can you analyse the statements and determine the killer?
A traveller comes to a fork in the road which leads to two villages. In one village the people always tell lies, and in the other village the people always tell the truth. The traveller needs to conduct business in the village where everyone tells the truth. A man from one of the villages is standing in the middle of the fork, but there is no indication of which village he is from. The traveller approaches the man and asks him one question. From the villager’s answer, he knows which road to follow. What did the traveller ask?
There was a man who went to the mall where he bought 3 pairs of red socks and 3 pairs of white socks. Another man who had already bought 3 pairs of red socks and 3 pairs of white socks was on the way back to return his 6 pairs of socks. They were both blind. As they were walking, they bumped into each other. All the socks scattered around the floor, but each pair remained held together by a rubber band. Nobody helped them pick the socks up, but in 3 minutes they both had 3 pairs of red, and 3 pairs of white. How is that possible if they are blind?
There are three jars filled with candies. One jar is filled with banana candies, one jar is filled with lemon candies and one jar has a mix of both. All the jars are mislabelled (i.e. all the jars have wrong labels about what kind of candies they contain). All the candies look very similar in shape, size and color and they even smell the same. The only way to distinguish them is by tasting. You have to eat one and only one candy to determine the correct jar labels. You can eat that one candy from any jar you want as long as you eat only one in total.
Every man in a village of 100 married couples has cheated on his wife. Every wife in the village instantly knows when a man other than her husband has cheated, but does not know when her own husband has. The village has a law that does not allow for adultery. Any wife who can prove that her husband is unfaithful must kill him that very day. The women of the village would never disobey this law. One day, the queen of the village visits and announces that at least one husband has been unfaithful. Everyone knows that the queen only speaks the truth. What happens?
A man goes into a barber shop and gets a haircut for $15. He pays the barber with a $20 bill, but the barber doesn’t have change. The barber goes to the neighboring flower shop and trades the $20 bill for a $10 dollar bill and two $5 bills. Then he gives the man his $5 in change. Later the lady from the flower shop confronts the barber and tells him that the $20 bill he gave her was counterfeit money. The barber agrees and he gives the lady a different $20 bill. Later that day he tries to figure out how much money he lost. How much money did the barber lose?
General Custer is surrounded by Indians and he’s the only cowboy left. He finds an old lamp in front of him and rubs it. Out pops a genie. The genie grants Custer one wish, with a catch. He says, “Whatever you wish for, each Indian will get two of the same thing.” Custer ponders a while and thinks:”If I get a bow and arrow they get two. If I get a rifle they get two!” He then rubs the bottle again and out pops the genie. “Well,” the genie asks “have you made up your mind?” What did Custer ask for to help him get away?
Tim and Pat were engaged by the local authorities to paint the lamp posts in a certain street. Tim, who was an early riser, arrived first on the job, and had painted three on the south side when Pat turned up and pointed out that Tim’s contract was for the north side. So Tim started afresh on the north side and Pat continued on the south. When Pat had finished his side he went across the street and painted six posts for Tim, and then the job was finished. There were an equal number of lamp-posts on each side of the street. Who painted more lamp posts, and how many more?
You are given two eggs, and access to a 100-storey building. Both eggs are identical. The aim is to find out the highest floor from which an egg will not break when dropped from a floor. If an egg is dropped and does not break, it is undamaged and can be dropped again. However, once an egg is broken, it cannot be used anymore. If an egg breaks when dropped from floor N, then it would also have broken from any floor above that. If an egg survives a fall from floor N, then it will also survive any fall below floor N. What is the minimum number of egg drops required to find the solution?
A group of campers have been on vacation so long, that they’ve forgotten the day of the week. The following conversation ensues.Darryl: What day is it? I don’t think it is Thursday, Friday or Saturday. Tracy: Well that doesn’t narrow it down much. Yesterday was Sunday. Melissa: Yesterday wasn’t Sunday, tomorrow is Sunday. Ben: The day after tomorrow is Saturday. Adrienne: The day before yesterday was Thursday. Susie: Tomorrow is Saturday. David: I know that the day after tomorrow is not Friday. If only one person’s statement is true, what day of the week is it?
During certain local floods five married couples found themselves surrounded by water, and had to escape from their unpleasant position in a boat that would only hold three persons at a time. Every husband was so jealous that he would not allow his wife to be in the boat or on either bank with another man (or with other men) unless he was himself present. Show the quickest way of getting these five men and their wives across into safety. Call the men A, B, C, D, E, and their respective wives a, b, c, d,e. To go over and return counts as two crossings. No tricks such as ropes, swimming, currents, etc., are permitted.
A bank is getting robbed and one of the robbers tells one of the tellers to give him all of the money. The teller tells him she doesn’t have access to it. Suddenly the phone rings. The robber tells the teller to answer it and not give them away. She picks up the phone and it happens to be her mother. She tells her mother “Is this an emergency mom? Call me when I get home, I could use some help painting.” Then she hangs up. The robbers continue to try to get into the vault but twenty minutes later the police show up with the tellers mom and arrest them all. How did the police know about the robbery?
Albert and Bernard became friends with Cheryl, and they want to know when her birthday is. Cheryl gives them a list of 10 possible dates. May 15 May 16 May 19 June 17 June 18 July 14 July 16 Aug 14 Aug 15 Aug 17 Cheryl then tells Albert and Bernard separately the month and the day of her birthday respectively. Albert: I don’t know when Cheryl’s birthday is, but I know that Bernard does not know too. Bernard: At first I don’t know when Cheryl’s birthday is, but I know now. Albert: Then I also know when Cheryl’s birthday is. When is Cheryl’s birthday?
You have three boxes. One has only red marbles, one has only blue marbles and the third has an equal number of red and blue marbles. The labels on the boxes have intentionally been switched so that each box is now marked incorrectly. Your job is to relabel the boxes correctly. Of course you could just look in the boxes to find out which labels match, but can you do it without looking into each box? Reach into any one of the boxes and select one marble. Can you now correctly label all three boxes? If not, select a second marble from any box. What is the fewest number of marbles you need to inspect in order to correctly label each box?
A poor farmer went to the market to sell some peas and lentils. However, as he had only one sack and didn’t want to mix peas and lentils, he poured in the peas first, tied the sack in the middle, and then filled the top portion of the sack with the lentils. At the market a rich innkeeper happened by with his own sack. He wanted to buy the peas, but he did not want the lentils. Pouring the seed anywhere else but the sacks is considered soiling. Trading sacks is not allowed. The farmer can’t cut a hole in his sack. How would you transfer the peas to the innkeeper’s sack, which he wants to keep, without soiling the produce?
