Can you name some countries which do not have the alphabet 'A' in them?

What work can one never finish?

What's a single-digit number with no value?

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

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?

What has 88 keys?

When I go in I might cause pain. I cause you to spit and ask you not to swallow. I can fill your hole. What am I?

It is a six-letter word.
The first four letters are me.
The second and last letters are the same.
The fourth second and last letter is payment.

Who is it?

You are trapped in a room with two doors. One leads to certain death and the other leads to freedom. You don't know which is which.
There are two robots guarding the doors. They will let you choose one door but upon doing so you must go through it.
You can, however, ask one robot one question. The problem is one robot always tells the truth, the other always lies and you don't know which is which.
What is the question you ask?

If one and a half boys, eat one and a half burgers in one and a half hours.

How many burgers can 9 boys eat in 3 hours?