They are the five precious gems of an everyday sort and all can be found on a Tennis Court. Who are they?

How is the moon similar to a dollar?

What does an Island and the letter T have in common?

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?

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

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

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?

What can you hold in your right hand, but never in your left hand?

I am a type of word that is spelt incorrectly or used differently, on purpose for humour. What am I?
Hint 1: You can find me in a joke.
Hint 2: I am a play on words.