If nine thousand, nine hundred nine dollars is written as $9,909,
how should twelve thousand, twelve hundred twelve dollars be written?

In the image below, you can see two glasses and two matchsticks.You need to move four matchsticks in such a manner that the crosses come inside the glasses. Note: you cannot move the crossed.

You bought me for dinner but never eat me. What am I?

Can you tell a 3D object that has just two surfaces?

Before Balboa discovered the Pacific Ocean, which was the largest ocean before that?

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?

On a certain island, people are gifted with assorted eye colours. There are a hundred green-coloured and a hundred grey-coloured pairs of eyes. On that island, there is no mirror available. Thus no one knows the eye color of their own. They could have asked each other but that is prohibited. They are not allowed to converse with each other. However, they can study and analyze other's eyes. They don't even know the statistics so it is believable to them that their eyes can be blue as well. There is a chance of freedom from the island. If anyone can guess the colour of his own eyes correctly, he will be set free and can leave the island.

On one particular day, an outsider comes to the island and announces that he has seen someone with grey colour eyes. What will happen now?

After teaching his class all about Roman numerals (X = 10, IX=9 and so on) the teacher asked his class to draw a single continuous line and turn IX into 6. The teacher's only stipulation was that the pen could not be lifted from the paper until the line was complete.

Do you know of a place where the wind blows south and then suddenly shifts direction towards the north?

I am a word that begins with the letter “i.” If you add the letter “a” to me, I become a new word with a different meaning, but that sounds exactly the same. What word am I?