When we see 2 but call 10?

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?

How can you drop a raw egg from a height onto a concrete floor without cracking it?

What is both possible and impossible at the same time?

Which alphabet letter is a question?

When does a USA Potato change its nationality?

It's a 7-letter word.
If we remove 1 letter from it, it remains the same.
If we remove 2 letters from it, it remains the same.
If we remove 3 letters from it, it remains the same.
If we remove all the letters from it, still it remains the same.
What is it?

You are on a Boat in the mid of a river. You have two cigarettes with you. One of these two you have to light, how will you light the cigarette?

If you had a pizza with crust thickness 'a' and radius 'z', what's the volume of the pizza?

What can you see in the middle of March and April that you can never see in any other month?