If you say my name, I will no longer exist. What am I?

If 5 cats catch 5 mice in 5 minutes, how long will it take one cat to catch a mouse?

What has one letter and starts with an E?

During which month do people sleep the least?

I am dry when I go inside, but wet when I am pulled outside.
The longer I am inside, the stronger I get
When I am completely out, I am wet and I literally sag
Who am I?

He digs out tiny caves and stores gold and silver in them. He also built bridges of silver and made crowns of gold. They are the smallest you could imagine. Sooner or later everybody needs his help, yet many people are afraid to let him help them. Who is he?

Why 1729 is a magic number? Answer Logically.

I have a clock(12-hour format) and both the needles of the clock overlap at 12:00.
After how much time, they will overlap again?

What is the Surname of Barbie Doll?

I have a hole in my back and legs I lack.
I live where I can’t breathe and I eat without teeth.
What am I?