Question: Four men walk into the desert. Suddenly all four are simultaneously knocked out. They awake buried to their heads in the sand unable to look anywhere but straight ahead. They are positioned so that each man sees another's head before him. However between the first and second man there is a separating wall. So the first man sees only desert. The second man sees only wall. The third man sees another's head and a wall. The fourth man sees two heads and a wall. On top of each mans head is a hat. The underside of each cap is black, but the outside of each cap is either blue or white. Before any of the men can speak, their captors tell them if they speak, they die. However, if any of them can guess the color of their cap on the first try they go free. The captors tell them that there are two blue caps and two white caps. Being an omniscient observer of the situation, we know that the order of the caps are: blue, white, blue, white. So knowing the perspective of each man in the sand, and that they can only see the color of caps/wall/desert in front of them, which of the four men knows for certain the color of his own cap. More importantly: why?
Answer: The third man. This is because he knows there are only two of each color cap. If the man behind him (the fourth man) saw two caps that were the same color in front of him, he would know that his own must be the opposite. However, because the caps alternate in color. The fourth man has only a 50% chance of getting his hat color correct, so therefore he stays quiet. The third man realizes that the fourth man is quiet because he must not see two caps of the same color in front of him, otherwise the fourth man would say the opposite of the caps in front of him. Therefore, the third man presumes his own cap must be the opposite of the mans in front of him, and his presumption is correct. Under this same logic, after the third man speaks his color hat, the second man, even though he sees only wall, would be the next to go free, because he knows his cap must be the opposite of whichever color the third mans cap was.
Question: There were 2 doors. Behind the 1 door, is hell and behind the other door, is heaven but you don't know which door will take you to heaven. In front of them, there were 2 brothers, which is guarding the door. One of the brother always lie and the other one always tell the truth. Of course you don't know who is lying and who is not. You only get 1 question to ask one of them to figure out which door leads to heaven. What question you might ask? Remember you only get to ask 1 question. it means that you can't ask one question each of them. that will be 2 questions. You only ask 1 question to any of them and no more. How do you do that?
Answer: Go up to one of the guy and ask this question, " Hello, which door that your brother will point if I ask him which way is the heaven." Then take the other door. Don't enter the door that he was pointing. This question will work for both of them because if you ask this question to the truth guy, he will point the hell because he knows that his brother will point hell and if you asked to the liar, he'll still point hell because he knows that his brother will point to heaven door, so he lied. That's why you take the other door.
Question: Alex was the strongest man in the world. He can lift up something that weighs 1000 kg easily. He can even pick up five women at once without any pain. But one day, there was a Weight Lifting Challenge Show. All the top 5 strongest man entered including Alex. The challenge is that they each have to lift up a really heavy object which weighs 1005 kg for five minutes. The winner is who didn’t drop it until it reached the time. If they all did it, the judges will decide to give first place to a person who can lift it up easily and stand still with no trouble looking. If Alex was the strongest man, he’ll probably come first. But he came second instead when the challenge was over. Why?
Answer: Because he’s not the strongest man anymore. He used to be the strongest man. Read the first sentence again (Alex was the strongest man in the world). He was the strongest but someone is stronger than him now.