A mother is 21 years older than her child. In exactly 6 years from now, the mother will be exactly 5 times as old as the child.
Where's the father?

What will you call your mother's brother's brother-in-law?

When my father was 31 I was 8. Now he is twice as old as me. How old am I?

Three doctors said that Bill was their brother. Bill says he has no brothers. How many brothers does Bill actually have?

How can one talk without saying a single word?

I have no life, but I can die. What am I?

If a zookeeper had 100 pairs of animals in her zoo, and two pairs of babies are born for each one of the original animals, then (sadly) 23 animals don’t survive, how many animals do you have left in total?

Imagine you are in a room with no windows or doors. How will you get out?

I am white when I am dirty, and black when I am clean. What am I?

Nine marbles are arranged in the image below. Can you slide two marbles to form a square?