During which month do people sleep the least?

I am not alive, but I grow; I don't have lungs, but I need air; I don't have a mouth, but water kills me. What am I?

Why Aeroplane windows are round?

There are seven sisters in a house in a village where there is no electricity or any gadget.

Sister-1: Reading Novel
Sister-2: Cooking
Sister-3: Playing Chess
Sister-4: Playing Sudoku
Sister-5: Washing clothes
Sister-6: Gardening

what is Sister-7 doing ?

what's the probability of getting a king or a queen from a pack of 52 cards?

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

Always in you, Sometimes on you;

If I surround you, I can kill you.

What am I?

When Jack was six years old he hammered a nail into his favourite tree to mark his height. Ten years later at age sixteen, Jack returned to see how much higher the nail was. If the tree grew by five centimetres each year, how much higher would the nail be?

How could a baby fall out of a twenty-story building onto the ground and live?

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