Question: A man taking the census walks up to the apartment of a mathematician and asks him if he has any children and how old they are. The mathematician says "I have three daughters and the product of their ages is 72." The man tells the mathematician that he needs more information, so the mathematician tells him "The sum of their ages is equal to our apartment number." The man still needs more information so the mathematician tells him "My oldest daughter has her own bed and the other two share bunk beds."
How old are his daughters?
Answer: His daughters are 8, 3, and 3. The prime factorization of 72 is 2 * 2 * 2 * 3 * 3, so the possible ages are 2, 3, 4, 6, 8, 9, 12, and 18. Using the prime factorization and these numbers the only combinations of numbers that work for the first clue are:
18, 2 and 2.
9, 4 and 2.
6, 6 and 2.
6, 4 and 3.
8, 3, and 3.
Since he doesn't know the ages after this piece of information the sum of the three numbers must not be unique. The sum of 8, 3, and 3; and 6, 6, and 2 are the same. Now the final clue comes in handy. Since we know that the oldest daughter has her own bed it is likely that she has the bed to herself and is older than the other two so there ages are 8, 3, and 3 rather than 2, 6 and 6.
Question: A man is found dead on a Sunday morning. His wife calls the police immediately. The police question the wife and staff. The wife said she was asleep, the cook said he was cooking breakfast, the gardener said she was picking vegetables, the butler said he was cleaning the closet, and the maid said she was getting the post. The police immediately arrested the murderer.Who was the murderer?
Answer: The maid because there's no post on Sundays.
Question: It is Halloween and your friends dare you to go into a haunted house. You creep up to the door, a little scared wondering what is behind the door. You go in and there is a long hallway leading out into a dark musty room with three doors. You're kind of scared once you are inside. You try to turn back, to get back outside, but when you turn around the door is closed and locked. You yell for help but there is only silence. The room is dark and you look for a light source. You see a light switch and try to turn it on. Sadly the power is out. You are terrified but have no choice but to follow the long hallway to the three doors in the pitch black. Behind one door is a bottomless pit with no end. Behind another door is an electric chair which you must sit in. Behind the last door is a pool full of acid. You must go in one of the rooms to the danger. Which one should you go through?
Answer: You should definitely go through the electric chair. Since the power is out, when you sit in the electric chair it will have no effect on you.
Question: Two men, Watson and Holmes, are out in the extremely dry forest. They are completely surrounded by a large forest fire on one side and a dangerous cliff on the other. The wind is blowing the forest fire towards them and the cliff. The fire will reach them in about one day.
Holmes turns to Watson, "I have matches, berries, and enough water for a day. We aren't going to die." How can they avoid getting swallowed up by the forest fire?
Answer: They can start a fire of their own with the matches and the wind will blow that fire in the same direction as the forest fire and they can take refuge in the section of the forest they burn down.