Question: You have been poisoned by an evil scientist. He told you that the only antidote is the saliva of a gecko. He contains saliva of six different animals. A gecko, a lizard, a koala, a tapir, a giraffe, and a cow. He hasn’t labeled he test tubes containing the saliva f the animals. On the left is a table which four of the test tubes are one. On the right is a table which two of the test tubes are on. The lizards saliva is poisonous. The lizard and gecko test tubes are on the same table. The test tubes on the left are labelled 1, 2, 3, and 4. The gecko spit will not override the lizard poison. The lizard and gecko saliva are not right beside each other. You don't know where the cow test tube is. You know that the cow saliva is in 2 or 3 however. You know that the lizard test tube is not to the right of the cow. You only have time to drink two test tubes, which side do you run toward and which test tubes do you drink?
Answer: You go to the left side and drink 4 and 3. You don't go to the right because there are only two test tubes on the right, and the lizard poison overrides the antidote to the other poison. The cow is in 2, which means that the lizard is in either 1 or 4, if the cow is 2 that means that the gecko is in 1, 2, or 3. We have deducted that the lizard is 1 or 4, lizard and gecko can't be beside each other and we know that the cow is in 2, which makes it impossible for the lizard saliva to be 3 or 4. Using that we can conclude the lizard is in 1. We use three and four because the gecko, through deduction, is in 3 or 4.
Question: You have a glass of water that looks about half full. How can you tell, only using the glass of water itself, if the glass is half full or not?
The glass is a right cylinder.
Answer: Tip the glass of water until the water reaches the rim of the glass and if the water lines up perfectly with the bottom rim of the glass, it is half full.
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.