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

I cannot talk, but I always reply when spoken to. What am I?

John is 45 years older than his son Jacob. If you find similarities between their ages, both of their ages contain prime numbers as the digits. Also, John's age is the reverse of Jacob's age.

Can you find their ages?

You are confined in a room and given two metal rods. Out of these two rods, one is magnet and the other is the iron rod. They look starkly similar. You don't have any other metal object in the room.

How will you decide which one of those is magnet?

Can you solve the maths in the below-given picture equation?

Luis Garavito killed Density x Volume.

Who is Luis Garavito ?

There is a square piece of paper with a hole that is denoted by the circle on the top right side in the given picture. You have to cut the paper in a manner that it forms two and only two separate pieces of paper and then rearrange the pieces in a manner that the holes come in the centre of the paper.

Name a key which is hardest to turn.

Nine marbles are arranged in the image below. Can you slide two marbles to form a square?

Paul's height is six feet, he's an assistant at a butcher's shop and wears size 9 shoes. What does he weigh?