Seven Brain Teasers

  1. What is the next number in the sequence? 1, 2, 4, 8, __.
  2. You are in an anteroom with two doors leading out. Behind one door is a coffer overflowing with jewels and gold, along with an exit. Behind the other door is an enormous, hungry lion that will pounce on anyone opening the door. You do not know which door leads to the treasure and exit and which door leads to the lion. With you in the anteroom are two other persons: The first is a knight, who always tells the truth; the other is a knave, who always lies. Both of these persons know what is behind each door. You, however, do not know which individual is the knight and which is the knave. You may ask one of the other persons just one question. What should you ask in order to be certain that you will open the door with the coffer behind it, instead of the hungry lion?
  3. What do the following words have in common?
    • baseball
    • football
    • soccer
    • hockey
    • telescope
  4. If I say to you, “The day before yesterday I was 25, and next year I will be 28,” then what day is my birthday?
  5. A pipe, a carrot, and a top hat are lying together in a field. Why?
  6. A man and his son are in a car accident. The father dies on the scene, but the child is rushed to the hospital. When he arrives, the surgeon says, “I can’t operate on this boy. He’s my son!” How can this be?
  7. Three people check into a hotel room for a night. The cost is $30, so they each pay $10. After they go to the room, the hotel’s cashier realizes that the cost should have been only $25, so he gives $5 to the bellhop and tells him to return the money to the guests. The bellhop realizes that $5 can’t be split evenly among the three guests, so he keeps $2 for himself and then gives the other $3 to the guests. Now the guests, with their dollars back, have each paid $9… for a total of $27. And the bellhop has pocketed $2. So there is $27 + $2, or $29, accounted for. But the guests originally paid $30. What happened to the other dollar?



  1. Those are the first five numbers I’m afraid of.
  2. This is a trick question. Knights look like knights, and knaves don’t. Knights carry swords. Ask the knight if you may borrow his sword. Use the sword to persuade the knave to pick which door to open. If he’s stupid enough to open the door with the lion behind it, he will get eaten, and you can have the jewels and gold. If he opens the door to the treasure room, run him through before he can grab the booty and get out the exit. Return the sword to the knight, with your thanks and some gold, before you leave. It’s just the right thing to do.
  3. Nothing.
  4. March 12. I don’t care what you think you figured out; my birthday is March 12.
  5. They are the three things the town drunk had on him when he wandered out into the field last night. When he finally passed out, wolves ate him. A brief prayer for his soul will be offered by the pastor on Sunday.
  6. The surgeon is mistaken, although this is certainly understandable. The boy’s face is really messed up from the car accident. The surgeon’s own son is just then huffing glue with his friends behind the Burger King and will be brought to the emergency room by ambulance later that evening.
  7. Call the f***ing police. There is a dollar missing! Nobody is going anywhere until we find that goddamned dollar. I’m dead serious.