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

What kind of band never plays music?

You have 10 balls with you. A friend of yours out of nowhere asks you to place those ten balls in five lines such that each of the lines has exactly 4 balls on them. He needs to check your intelligence. Prove him by doing the task.

The day before yesterday I was 25 and the next year I will be 28. This is true only one day in a year. What day is my birthday?

When is the top of a mountain similar to a savings account?

An infinite number of mathematicians are standing behind a bar. The first asks the barman for half a pint of beer, the second for a quarter pint, the third an eighth, and so on. How many pints of beer will the barman need to fulfill all mathematicians' wishes?

One of the leprechaun is missing if you see the two pictures attached to this question. Where did he go? When he comes back, do you know where has he been?

As you can see that fifteen matches have been used to form an arrangement. What you have to do is remove any six of them to make them ten.

The more of this there is, the less you see. What is it?

Can you find out which number multiplied by itself will give the output as 12345678987654321?