If I put in one canary per cage, I have one bird too many. If I put in two canaries per cage, I have one cage too many. How many cages and canaries do I have?

Two in a corner, one in a room, zero in a house, but one in a shelter. What am I?

What is black when you buy it, red when you use it, and gray when you throw it away?

You want to boil a two-minute egg. If you only have a three-minute timer (hourglass), a four-minute timer and a five-minute timer, how can you boil the egg for only two minutes?

It has horns but can’t beep. It is like to bleat but It is not a sheep. What is it?

A girl has as many brothers as sisters, but each brother has only half as many brothers as sisters. How many brothers and sisters are there in the family?

A shepherd had 18 sheep, out of which, all but ten died.

Can you tell us how many sheep was he left with?

Three ants are sitting at the three corners of an equilateral triangle. Each ant starts randomly picks a direction and starts to move along the edge of the triangle. What is the probability that none of the ants collide?

What mathematical symbol can be put between 5 and 9, to get a number bigger than 5 and smaller than 9?

Replace the question mark with the correct number.