1. You and a friend are playing a game, taking turns in placing quarters on a round table. You both have an unlimited number of quarters but are not allowed to go beyond a single layer. The winner is who places the last quarter so that there is no more free space left on the table for another. If you have the choice whether to move first or second, which should you choose? What would be your strategy?
  2. Four people have to cross a shaky dilapidated bridge over a raging river at night. To cross safely, they need a flashlight, but they have only one and the bridge will only hold two people at once. The first person can cross the bridge in one minute, the second in two, the third in five, and the fourth in ten. What is the shortest time in which they can all get to the other side? This is an honest problem, please no "throwing flashlight across the river." :) Also, if your answer is 19 minutes, think again!
  3. You are given digits 1, 3, 4, 6 and allowed to add, multiply, subtract, delete and use brackets. For example, 4*(6/3+1) gives 12. Can you get 24? No uniting of digits or using powers is allowed, such as in 3*(14-6) or 6*(14+3). You also have to use each digit exactly once, so 4*6 does not work either.