• Brain Teasers & Puzzles

    Questions Per Page:
    • A stark raving mad king tells his 100 wisest men he is about to line them up and that he will place either a red or blue hat on each of their heads. Once lined up, they must not communicate amongst themselves. Nor may they attempt to look behind them or remove their own hat.

      The king tells the wise men that they will be able to see all the hats in front of them. They will not be able to see the color of their own hat or the hats behind them, although they will be able to hear the answers from all those behind them.

      The king will then start with the wise man in the back and ask “what color is your hat?” The wise man will only be allowed to answer “red” or “blue,” nothing more. If the answer is incorrect then the wise man will be silently killed. If the answer is correct then the wise man may live but must remain absolutely silent.

      The king will then move on to the next wise man and repeat the question.

      The king makes it clear that if anyone breaks the rules then all the wise men will die, then allows the wise men to consult before lining them up. The king listens in while the wise men consult each other to make sure they don’t devise a plan to cheat. To communicate anything more than their guess of red or blue by coughing or shuffling would be breaking the rules.

      What is the maximum number of men they can be guaranteed to save?

      View Solution
      Submit Solution
      • 1,463.6K views
      • 1 answers
      • 0 votes

    • You are the ruler of a medieval empire and you are about to have a celebration tomorrow. The celebration is the most important party you have ever hosted. You’ve got 1000 bottles of wine you were planning to open for the celebration, but you find out that one of them is poisoned.

      The poison exhibits no symptoms until death. Death occurs within ten to twenty hours after consuming even the minutest amount of poison.

      You have over a thousand slaves at your disposal and just under 24 hours to determine which single bottle is poisoned.

      You have a handful of prisoners about to be executed, and it would mar your celebration to have anyone else killed.

      What is the smallest number of prisoners you must have to drink from the bottles to be absolutely sure to find the poisoned bottle within 24 hours?

      View Solution
      Submit Solution
      • 1,463.6K views
      • 1 answers
      • 0 votes


    • A frog is at the bottom of a 30 meter well. Each day he summons enough energy for one 3 meter leap up the well. Exhausted, he then hangs there for the rest of the day. At night, while he is asleep, he slips 2 meters backwards. How many days does it take him to escape from the well?

      Note: Assume after the first leap that his hind legs are exactly three meters up the well. His hind legs must clear the well for him to escape.

      View Solution
      Submit Solution
      • 1,463.3K views
      • 1 answers
      • 0 votes



    • You are trapped in a room with two doors. One leads to certain death and the other leads to freedom. You don’t know which is which.

      There are two robots guarding the doors. They will let you choose one door but upon doing so you must go through it.

      You can, however, ask one robot one question. The problem is one robot always tells the truth ,the other always lies and you don’t know which is which.

      What is the question you ask?

      View Solution
      Submit Solution
      • 1,466.4K views
      • 1 answers
      • -1 votes

    • Four angels sat on the Christmas tree amidst other ornaments. Two had blue halos and two – yellow. However, none of them could see above his head. Angel A sat on the top branch and could see the angels B and C, who sat below him. Angel B, could see angel C who sat on the lower branch. And angel D stood at the base of the tree obscured from view by a thicket of branches, so no one could see him and he could not see anyone either.
      Which one of them could be the first to guess the color of his halo and speak it out loud for all other angels to hear?

      View Solution
      Submit Solution
      • 1,465.6K views
      • 1 answers
      • 0 votes

    • Three Palefaces were taken captive by a hostile Indian tribe. According to tribe’s custom they had to pass an intelligence test, or die.
      The chieftain showed 5 headbands – 2 red and 3 white. The 3 men were blindfolded and positioned one after another, face to back. The chief put a headband on each of their heads, hid two remaining headbands, and removed their blindfolds. So the third man could see the headbands on the two men in front of him, the second man could see the headband on the first, and the first could not see any headbands at all.
      According to the rules any one of the three men could speak first and try to guess his headband color. And if he guessed correctly – they passed the test and could go free, if not – they failed. It so happened that all 3 Palefaces were prominent logicians from a nearby academy. So after a few moments of silence, the first man in the line said: “My headband is …”.
      What color was his head band? Why?

      View Solution
      Submit Solution
      • 1,464.3K views
      • 1 answers
      • 0 votes



    • After losing the “Spot on the Forehead” contest, the two defeated Puzzle Masters complained that the winner had made a slight pause before raising his hand, thus derailing their deductive reasoning train of thought. And so the Grand Master vowed to set up a truly fair test to reveal the best logician amongst them.
      He showed the three men 5 hats – two white and three black. Then he turned off the lights in the room and put a hat on each Puzzle Master’s head. After that the old sage hid the remaining two hats, but before he could turn the lights on, one of the Masters, as chance would have it, the winner of the previous contest, announced the color of his hat. And he was right once again.
      What color was his hat? What could have been his reasoning?

      View Solution
      Submit Solution
      • 1,466.8K views
      • 1 answers
      • 0 votes

    • Three Masters of Logic wanted to find out who was the wisest amongst them. So they turned to their Grand Master, asking to resolve their dispute.
      “Easy,” the old sage said. “I will blindfold you and paint either red, or blue dot on each man’s forehead. When I take your blindfolds off, if you see at least one red dot, raise your hand. The one, who guesses the color of the dot on his forehead first, wins.”
      And so it was said, and so it was done. The Grand Master blindfolded the three contestants and painted red dots on every one. When he took their blindfolds off, all three men raised their hands as the rules required, and sat in silence pondering. Finally, one of them said: “I have a red dot on my forehead.”
      How did he guess?

      View Solution
      Submit Solution
      • 1,463.9K views
      • 2 answers
      • 0 votes

    • One absentminded ancient philosopher forgot to wind up his only clock in the house. He had no radio, TV, telephone, internet, or any other means for telling time. So he traveled on foot to his friend’s place few miles down the straight desert road. He stayed at his friend’s house for the night and when he came back home, he knew how to set his clock.
      How did he know?

      View Solution
      Submit Solution
      • 1,463.6K views
      • 1 answers
      • 0 votes



    • Three cannibals and three anthropologists have to cross a river.

      The boat they have is only big enough for two people. The cannibals will do as requested, even if they are on the other side of the river, with one exception. If at any point in time there are more cannibals on one side of the river than anthropologists, the cannibals will eat them.

      What plan can the anthropologists use for crossing the river so they don’t get eaten?

      Note: One anthropologist can not control two cannibals on land, nor can one anthropologist on land control two cannibals on the boat if they are all on the same side of the river. This means an anthropologist will not survive being rowed across the river by a cannibal if there is one cannibal on the other side.

      View Solution
      Submit Solution
      • 1,499.9K views
      • 1 answers
      • 2 votes

  • More puzzles to try-