By Martin Gardner
Question: You are in a room with two metal rods and no other metal. One of them is magnetized and the other is not.
How can you determine which one is magnetized and which is not?
Answer: Solution 1: Touch the end of one bar (A) to the middle of the other bar (B) forming a 'T' shape. If the bars are attracted then bar A is magnetized and if they are not attracted then bar B is the magnet. This is because magnets have fields at the poles (the ends) but not in the middle. So the end would attract and middle would not.
Solution 2: Hang a rod from the ceiling and if it turns north than it is the magnetized rod.
Question: There is an island with exactly 201 residents, 100 with blue eyes, 100 with brown eyes, and the island leader (who has green eyes). To leave the island, one must know their own eye color. There are no reflective surfaces on the island and no on can communicate with each other other than the leader to the residents. No one on the island knows how many of each eye color there is. Everyone on the island is a perfect logician, meaning that if there us a solution they'll find it. Every morning the leader gives anyone a chance to leave the island by guessing their eye color. One morning, the leader gathers all 200 residents to make an announcement, he says "at least 1 person on this island has blue eyes" How many people leave the island and in how many days after the announcement? Notes: this is known as one of the hardest riddles ever
Answer: ANSWER: all 100 blue eyed people in 100 days. EXPLANATION: imagine there is only 1 person on the island, he will look around and see that there are no blue eyed people, he will then know his eye color in 1 day, if there are two, each will see that there is 1 blue eyed person, of this person doesn't leave on the 1st day, that means that he must also have blue eyes so that the same rules apply to the other man's perspective, following this logic, n= blue eyed people and d= days so d=n because for each person added, one more day is needed to know their own eye color. if you would like more info, search "100 blue eyes riddle"
Question: In the harbor of a small town, there is a large boat. Coming off of the boat is a ladder reaching down so that the bottom rung is just above the surface of the water. As the tide comes in, the water rises at 1 foot every 30 minutes, and continues like this for 3 hours. If the rungs are each 1 foot apart, how many rungs are under water when the tide stops rising?
Answer: No rungs are under water. The ladder is attached to a boat which rises with the tide, therefore, the bottom rung will stay just above the surface of the water.