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

Akbar summoned Birbal out of anger.
He told him that he will have to face death.
He asked him to make a statement and if the statement is true he will be buried alive and if the statement is false, he will be thrown at lions.
After hearing Birbal’s statement, Akbar could do nothing but smile.
He gave him 5 gold bars and let him go.

What did Birbal say?

You are mixing a mixture of cement and Sand with five gallons of water. You have a garden hose giving you all the water you need. The problem is that you only have a four-gallon bucket and a seven-gallon bucket and neither has graduation marks. Find a method to measure five gallons.

I am the beginning of the end, and the end of time and space. I am essential to creation, and I surround every place. What am I?

There is a five-letter word which has 3 consonants(all are same) and 2 different vowels.
Also, something wrong is associated with the word.

Can you name it?

What four weights can be used to balance from 1 to 30 pounds?

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

Can you find the hidden animal in the picture below?

A finger goes in me. You fiddle with me when you're bored. The best man always has me first. What am I?

At a party, there are five people and a whole round cake lying at the centre of the table. Only four people will make a cut and take their piece and the last one will get the remaining piece on the table. How can they make sure that everyone gets a 1/5th of the piece?