What brings you down but never up?

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

It's pretty hard to give up.
If you remove a part of it, you will be left with a bit.
Even if you remove another part, the bit still remains.
Remove one more and it still remains.

What is it?

Why is it very easy to weigh a fish?

If I put in one canary per cage, I have one bird too many. If I put in two canaries per cage, I have one cage too many. How many cages and canaries do I have?

If you were to put a coin into an empty bottle and then insert a cork into the neck, how could you remove the coin without taking out the cork or breaking the bottle?

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?

I’m tall when I’m young, and I’m short when I’m old. What am I?

What has a ring but no finger?

What is both possible and impossible at the same time?