There are forty elephants and they have forty-fore heads. How can this be possible?

What does below rebus means ?

When is the top of a mountain similar to a savings account?

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?

A sea diver is a real show-off. He showed everyone that he can hold his breath underwater for 15 minutes.

I went to the diver and told him that I can be underwater for double the time i.e 30 minutes.
He responded that he will give me 100$ if I would be able to do it. I won 100$.

What did I do?

I am five letter word that is under you.
If you remove my 1st letter, then I am over you.
If you remove my 1st and 2nd letters then I am all around you.

Who am I?

Four men were in a boat on the lake. The boat turns over, and all four men sink to the bottom of the lake, yet not a single man got wet! Why?

How many minutes are there in Feb 2017?

Note: The shortest answer is the correct answer.

How many words can a quill made with the feather of a pigeon write with a 100ml bottle of black ink?

How many words can a pen with half refill write?