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

There are two arch enemies Messi and Ronaldo who hate each other to an extreme. One day both were going together and a Jeanie appeared in front of them. Jeanie grants 3 wishes to Ronaldo and one to Messi.

Messi replied smartly 'Give me twice whatever Ronaldo demands'.

Ronaldo asked his 1st wish 'Give me 10000 billion dollars. Soon Messi gets 2000 billion dollars.
Ronaldo asked for his 2nd wish 'Give me one mansion in every country in the world. Soon Messi gets two mansions in every country of the world?

What should be Ronaldo's third wish?

Count the Triangle in the figure given below:

One day, John and his friends were playing around. Jacob hit something with a Pin and it popped. John's dad came into the room that very moment, but he wasn't mad. In fact, he was smiling. What did Jacob hit?

Identify the movie name through below Rebus containing Pi Mouse and coconut tree..

What does this mathematical rebus means ?

Write the next letter in this sequence.
O, T, T, F, F, S, S, E, __
**Hint: It is a Number Series Puzzle

A chess tournament is taking place on knock-out terms (the one who loses the match is out of the game).
(a) If 10 matches are played in total, how many players participated?
(b) If 20 players took part in the tournament, how many matches were played?

Mr Black, Mr Gray, and Mr White are fighting in a truel. They each get a gun and take turns shooting at each other until only one person is left. Mr Black, who hits his shot 1/3 of the time, gets to shoot first. Mr Gray, who hits his shot 2/3 of the time, gets to shoot next, assuming he is still alive. Mr White, who hits his shot all the time, shoots next, assuming he is also alive. The cycle repeats. If you are Mr Black, where should you shoot first for the highest chance of survival?

An explorer goes on an exposition in the jungle. He sets up camp in the middle of the jungle. The next morning he sees something with a head and a tail, but he is not afraid. What did he see in his bag?