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?

What is the relationship between these matchstick pictures below?

If there are fifteen crows on a fence and the farmer shoots a third of them, how many crows are left?

Can you make numbers like 24, using numbers 3,3,7 & 7 with any arithmetic operator?

Consider this: Arnold Schwarzenegger has a big one. Michael J. Fox has a small one. Prince doesn’t have one. The Pope has one but never uses it. Bill Clinton has one and uses it all the time. What is it?

How is a fly different from a mosquito?

Can you count the number of quadrilaterals in the picture below?

What number comes next in this sequence:
7 8 5 5 3 4 4 _

An ant is travelling on a 1-meter-long rope at 1 cm/second but also the entire rope is being stretched by an extra 1 meter/second. Is it possible for the ant to reach at the end of the rope?

What runs around the whole yard without moving?