An artist while painting a scenic beauty, decides to paint three layers of blue colour on the sky.

Which layer will go on the first?

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

Can you name four days which start with the letter 'T'?

What type of tree can I carry in my hand?

I am a type of room you cannot enter or leave. Raised from the ground below, I could be poisonous or a delicious treat. What am I?

John killed hundreds of people mercilessly and yet the police were not able to put her behind the bars. Why?

My friends called me Iron59 because my parents are a chemist and a mathematician. What is my real name?

It begins where the time ends.
Its second is an expression of surprise.
Its third is a question.
Its fourth is urinate.
It ends with a drink.

Which country it is?

A word I know,
Six letters contain,
Subtract just one,
And twelve is what remains.

It's a protector.
It sits on a bridge.
One individual can see directly through it, while others wonder what it hides.

What is it?