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

You may enter, but you may not come in. I have space, but no room. I have keys, but open no lock. What am I?

What has many keys but can’t open a single lock?

My friends called me Iron59 because my parents are a chemist and a mathematician. What is my real name?

On her drawing table, Sayna lit 12 coloured candles. A few seconds later she blew two candles off.

How many candles Sayna have at the end?

Living above a star, I do not burn
Eleven friends and they do not turn
I can just be visited in a sequence, not once or repeatedly
PQRS are my initials
Can you tell my name accurately?

John can eat 27 chocolates in an hour, Jacob can eat 2 chocolates in 10 minutes, and Jolly can eat 7 chocolates in 20 minutes. How long will it take them to share and eat a box of 120 chocolates whilst playing Chess?

John and Jacob are twin brothers. One of them is a liar whereas the other one is a truth-teller.

I called their home number and one of them picked up.
I asked. 'Does John lie?' The person replied with a yes.

Whom did I talk with, John or Jacob?

In the picture given below, can you find out which digit will take place of the question mark?

John was piloting a plane behind a car but was never able to overtake it. Why?