Answer:
How do you discover something that does not exist?
There are 5 sisters in a room: Ann is reading a book, Margaret is cooking, Kate is playing chess, Marie is doing the laundry. What is the fifth sister doing?
A man is able to contact his long lost brother who has never met. They agree to meet. When the brother arrives he is able to instantly pick him out from the crowd. How is that possible?
The more that there is of this, the less you see. What is it?
What can you fill a room with that takes up no space?
I’m grown from darkness but shine with a pale light. Very round I am and always a lady's delight.