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

Replace the question mark with the number below given a simple math problem.

I don't get anymore wetter, no matter how much rain falls on me.

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?

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

Can you find the next number in the below sequence
3 , 7 , 10 , 11 , 12 , 17 ?

In which direction should the missing arrow point?

A mathematician couple was having a Frappuccino in Starbucks sitting opposite to each other. Suddenly the guy noticed the text written on the paper in front of them and exclaimed that it was wrong. The girl denied it and said it is appropriate. Both are correct. What is written on the paper?

Why do people go to bed?

There is a family that live in a round house. The two parents go out for a movie and leave a babysitter to watch their son. They come back and the kid was not there. Some one kidnapped him. The maid said she was cleaning in a corner. The cook said he was making pizza. The babysitter said she was getting a board game. Who kidnapped him.