During which month do people sleep the least?

I am looking for a word that change both gender and number when i add the letter 'S'.

What Word am I Looking For ?

Before Mount Everest was discovered, what was the highest mountain in the world?

I’m light as a feather, yet the strongest person can’t hold me for five minutes. What am I?

A man calls his dog from the opposite side of a river. The dog crosses the river without a bridge or a boat and manages to not get wet. How is this possible?

There are a number of books on a shelf. If one book is the 4th from the left and 6th from the right, how many books are on the shelf?

I have a big mouth and I am also quite loud! I am NOT a gossip but I do get involved with everyone's dirty business.

Two in a corner, one in a room, zero in a house, but one in a shelter. What is it?

If you say my name, I will no longer exist. What am I?

You Throw The Outside, Cook The Inside
Eat The Outside, Throw The Inside.

What Is It?