Brain Puzzles

There is a room with a door (closed) and three light bulbs (initially switched off). Outside the room there are three switches, connected to the bulbs. You may manipulate the switches as you wish, but once you open the door you can’t change them. Identify each switch with its bulb.

Switches : S1,S2 and S3
Bulbs : B1, B2 and B3

If you are on a boat and you throw out a suitcase, Will the level of water increase?

Here are three answers:

1. Answer A
2. Answer A or B
3. Answer B or C

There is only one correct answer to this question. Which answer is it?

A woman shoots her husband. Then she holds him under water for over 5 minutes. Finally, she hangs him. But 5 minutes later they both go out together and enjoy a wonderful dinner together. How can this be?

A murderer is condemned to death. He has to choose between three rooms. The first is full of raging fires, the second is full of assassins with loaded guns, and the third is full of lions that haven’t eaten in 3 years. Which room is safest for him?

Five men and five boys have to cross the Ganga River to attend a birthday party. They have only one row boat with them. Because of the small size of the row boat, the boat can not carry more than one man, or more than two boys. Thus, a man riding with a boy would not be possible. What would be the least number of boat trips that would take everyone to the other shore?

Mrs. Green, Mrs. Brown, and Mrs. Blue attended a Halloween Party. They came wearing green, brown, and blue costumes but not necessarily in their respective order. Mrs. Green said to the lady wearing the brown costume, “Did you notice that the three of us are wearing costumes having colors not corresponding to our names?”

Determine which colored costume each of them wore during the Halloween Party.

During the age of the medieval empires, when knights and barbarians fought against each others, a man was captured and sentenced to death for allegedly befriending barbarians. The king, however, wanted to give him another chance. The king ordered him to his presence and ask him to choose one of the three knights present. One of the knights is the Knight of Life, and he always tells the truth. The second Knight is the Knight of Death, and he always tells lies. The third knight is the Knight of the Dungeon. He sometimes lies and sometimes tells the truth. If the man chooses the Knight of Death, he is to be executed before sunset. If he chooses the Knight of Life, he would be acquitted and set free right away. If he chooses the Knight of the Dungeon, he would spend the rest of his life imprisoned in the Dungeon. This is the first time the man ever saw these knights and could not recognize them. However, the man is allowed to ask these three knights one question each. Thus, the man asked the red hair knight, “What is the name of this blond hair knight?” The reply was “He is the Knight of the Life.” He asked the black hair knight, “What is the name of this blond hair knight?” The reply was “He is the Knight of Death.” Then he asked the blond hair knight “Who are you?” “I am the Knight of the Dungeon” was the reply. Luckily, the man was able to correctly choose the Knight of Life, and was set free immediately. Can you identify who was the Knight of Life, and also who the other two knights were?

It is noon, your lunch hour, but you cannot go out because there is a terrific hailstorm. Turning on your radio you hear the weather caster predict that the hail will change to rain and that it will pour all day today. How can you determine whether the sun will be shining in 36 hours?

100 C# programmers are lined up in a row by an assassin. The assassin puts red and blue hats on them. They can’t see their own hats, but they can see the hats of the people in front of them. The assassin starts in the back and says “what color is your hat?” the C# programmer can only answer “red” or “blue.” The programmer is killed if he gives the wrong answer; then the assassin moves on to the next programmer. The programmers in front get to hear the answers of the programmers behind them, but not whether they live or die. They can consult and agree on a strategy before being lined up, but after being lined up and having the hats put on, they can’t communicate in any way other than those already specified. What strategy should they choose to maximize the number of programmers who are guaranteed to be saved?