##### 100 blue eyes island (hard)

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

##### Easy Riddle #98 (hard)

Question: Suppose you're on a game show, and you're given the choice of three doors: Behind one door is a sports car; behind all of the others is bicycles. You pick a door, say No. 1, and the host, who knows what's behind the doors, opens another door, say No. 2, revealing a bicycle. He then says to you, "Do you want to pick door No. 3?" Is it to your advantage to switch your choice?

##### Easy Riddle #99 (hard)

Question: How many people do you need to have the odds be in favor (at least 50% chance) of two people having the same birthday?

##### Easy Riddle #266 (hard)

Question: You have a cup of tea (A) and a cup of coffee (B) (equal amounts), and you take a spoonful of the coffee (B) and mix it thoroughly into the tea (A). Then you take a spoonful of tea (A) and mix it with the coffee (B). Does the cup that originally had tea in it (A) have more coffee or does the cup that originally had coffee in it (B) have more tea?

##### All rung up (hard)

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?