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

I get hot but I never sweat,
I cook food but I am not a chef,
I have a door but you can't enter me,
I have a light but I am not a lamp.
Who am I?

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.

There are four 3-link chains. All you have to do is join them into a big 12-link chain. For joining two closed links, one of the links must be cut and placed onto the other link for closing.

How many minimum links will you have to cut to make the big chain?

You throw me out when you want to use me and you take me in when you don't want to use me.

Who Am I?

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

What Word am I Looking For ?

John was going on a jungle trip. He asked his wife to pack something to eat, something to drink and something to burn if he feels cold in the jungle. When John opens the backpack he found just one thing in the bag. What was it?

I have no life, but I can die. What am I?

I have a hole in my back and legs I lack.
I live where I can’t breathe and I eat without teeth.
What am I?

What is more useful when it is broken?