The host of a game show offers the guest a choice of three doors. Behind one is an 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’m orange, I wear a green hat and I sound like a parrot. What am I?

You enter your friend's room. He is not in his room. Although you see that on the bed there are two dogs, five cats, two giraffes and three pigs. Also, a couple of chickens and ducks are flying in the room.

Calculate the number of legs standing on the floor.

Count the number of triangles in the picture below:

The doctor prescribed you to take one pill from the bottle every half an hour. The bottle is now left with only three pills.

How long do you think you have before you run out of pills?

Find the missing letter in the last circle logically in the given below picture.

What is the centre of gravity?

What's the next in the series?

H, Be, F, S, Mn, Kr, In, Gd, Tl, ?

You can hear me, but you can't touch or see me.

What am I?

If it took eight men ten hours to build a wall, how long would it take four men to build it?