The host of a game show, offers the guest a choice of three doors. Behind one is a expensive car, but behind the other two are goats.
After you have chosen one door, he reveals one of the other two doors behind which is a goat (he wouldn't reveal a car).

Now he gives you the chance to switch to the other unrevealed door or stay at your initial choice. You will then get what is behind that door.

You cannot hear the goats from behind the doors, or in any way know which door has the prize.

Should you stay, or switch, or doesn't it matter?

I am the one who remains awake when you sleep. But I need to rest when you awake. Who Am I?

If eleven plus two equals one, what does nine plus five equal?

Which three-digit number, made of consecutive digits, like 567, is 2 less than a cube and 2 more than a square?

In a stable, there are men and horses. In all, there are 22 heads and 72 feet. How many men and how many horses are in the stable

What is the largest number you can write with just 3 digits?

Our product and our sum always give the same answer. Who are we?

Why is 6 afraid of 7?

Count the number of triangles in the picture below:

Can you name three consecutive days without using the words Monday, Tuesday, Wednesday, Thursday, Friday, Saturday, or Sunday?