What is more useful when it is broken?

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?

You walk into a room that contains a match, a kerosene lamp, a candle and a fireplace. What would you light first?

Find The Next Number in the series:

12 13 15 17 111 113 117 119 123 ?

Can you think of a smallest +ve number such that if we shuffle the digits of the number, the new number becomes double the original number?

On one occasion, A Boy collects 71 rupees in form of 20 paise and 25 paise. He collects a total of 324 coins.

Can you tell me how many 20-paisa and 25-paisa he got?

This is a most unusual paragraph. How quickly can you find out what is so unusual about it? It looks so ordinary, you'd think nothing was wrong with it. Actually, nothing IS wrong with it. But it is not as ordinary as you might think. If you think about it for a bit, you will find out why it is truly so unusual. So what is it? What is so unordinary about this paragraph?

What is the largest amount of money that you can possess in change and still if someone asks you for a dollar, you won't be able to give?

why number 8549176320 is one of a kind?

A man has a barrel filled with oil that weighs 100 pounds, and then he puts something into it. Now the barrel weighs less than 100 pounds. What did he put in the barrel?