Look at this sequence from top to bottom. What is the next number in the sequence?
1
11
21
1211
111221
312211

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?

There was a greenhouse.
Inside the greenhouse, there is a white house.
Inside the white house, there is a red house.
Inside the red house, there are lots of babies.

What is It?

When I get multiplied by any number, the sum of the figures in the product is always me. What am I?

Can you count the number of squares in the given picture?

You are given a cube that is made with the help of 10x10x10 smaller cubes summing up to a total of 1000 smaller cubes. You are asked to take off one layer of the cubes.
How many remain now?

First, think of the colour of clouds. Next think the colour of snow. Last, think of the colour of the moon. Now, what do cows drink?

Can it be possible to build a house that has all its four walls facing towards the South?

What has 13 hearts but no other organs?

How many words can a quill made with the feather of a pigeon write with a 100ml bottle of black ink?