It's 7:00 am. You are asleep and there is a sudden knock on the door.
Behind the door are your parents, who came to have breakfast.
In your fridge: bread, pasteurised milk, juice, and a jar of jam.
What will you open first?
Scientists have proven that cats have more hair on one side than their other side. Some people believe that this is because when cats lay on their side they need insulation from the cold on the floor or ground. Which side of a cat has more hair?
You can easily "tile" an 8x8 chessboard with 32 2x1 tiles, meaning that you can place these 32 tiles on the board and cover every square.
But if you take away two opposite corners from the chessboard, it becomes impossible to tile this new 62-square board.
Can you explain why tiling this board isn't possible?
Color in the chessboard, alternating with red and blue tiles. Then color all of your tiles half red and half blue. Whenever you place a tile down, you can always make it so that the red part of the tile is on a red square and the blue part of the tile is on the blue square.
Since you'll need to place 31 tiles on the board (to cover the 62 squares), you would have to be able to cover 31 red squares and 31 blue squares. But when you took away the two corners, you can see that you are taking away two red spaces, leaving 30 red squares and 32 blue squares. There is no way to cover 30 red squares and 32 blue squares with the 31 tiles, since these tiles can only cover 31 red squares and 31 blue squares, and thus, tiling this board is not possible.
You are driving a car on one big stormy night. You pass a bus station. There are three people who are waiting for the bus: One old sick lady who is dying, One doctor who saved your life before, and one lady who is someone you have been dreaming to be with. You can only take one passenger, which one will you choose?
Give the car key to the doctor, let the doctor take the old lady to the hospital and stay to wait for the bus with the lady of your dreams!
A woman who lived in Germany during World War II wanted to cross the German/Swiss border in order to escape Nazi pursuers. The bridge which she is to cross is a half mile across, over a large canyon. Every three minutes a guard comes out of his bunker and checks if anyone is on the bridge. If a person is caught trying to escape German side to the Swiss side they are shot. If caught crossing the other direction without papers they are sent back. She knows that it takes at least five minutes to cross the bridge, in which time the guard will see her crossing and shoot her. How does she get across?
She waits until the guard goes inside his hunt, and begins to walk across the bridge. She gets a little more than half way, turns around, and begins to walk toward the german side once more. The guard comes out, sees that she has no papers, and sends her "back" to the swiss side.