(1) The Ball
Q. How can you throw a ball as hard as you can and have it come back to you, even if it doesn’t bounce off anything? There is nothing attached to it, and no one else catches or throws it back to you.
A. Throw the ball straight up in the air.
(2) Which Switch?
Q. There are three switches downstairs. Each corresponds to one of the three light bulbs in the attic. You can turn the switches on and off and leave them in any position. How would you identify which switch corresponds to which light bulb, if you are only allowed one trip upstairs?
A. Keep the first bulb switched on for a few minutes. It gets warm, right? So all you have to do then is … switch it off, switch another one on, walk into the room with bulbs, touch them and tell which one was switched on as the first one (the warm one) and the others can be easily identified
(3) A Man in an Elevator
Q. A man who lives on the tenth floor takes the elevator down to the first floor every morning and goes to work. In the evening, when he comes back; on a rainy day, or if there are other people in the elevator, he goes to his floor directly. Otherwise, he goes to the seventh floor and walks up three flights of stairs to his apartment.
Can you explain why?
A. The man is of short stature. He can’t reach the upper elevator buttons, but he can ask people to push them for him. He can also push them with his umbrella.