What has many teeth, but cannot bite?

What time is it when an elephant sits on a fence?

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?

When it\’s bad luck to meet a black cat?

Prove that twice of ten is the same as twice of eleven.

Which country gets ill every time?

How many words can a pen with half refill write?

How can you tell a raw egg from a hard-boiled egg?