Spot what is wrong here in below Picture?

Which part of London exists in France as well ?

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?

I never was there, I am always to be.
You have never ever seen me, not ever you will.
Yet I am the confidence of everyone.

Who Am I?

You are a prisoner sentenced to death. The Emperor offers you a chance to live by playing a simple game. He gives you 50 black marbles, 50 white marbles, and 2 empty bowls. He then says, 'Divide these 100 marbles into these 2 bowls. You can divide them any way you like as long as you use all the marbles. Then I will blindfold you and mix the bowls around. You then can choose one bowl and remove ONE marble. If the marble is WHITE you will live, but if the marble is BLACK... you will die.'

How do you divide the marbles up so that you have the greatest probability of choosing a WHITE marble?

As easy as you can get into me, it is as hard to get out of me.

Do you know what I am?

Can you arrange four 9's and use at most 2 math symbols, to make the total 100?

You need to remove two matchsticks to make the below equation true. Can you do it ?

You are in a room with no metal objects except for two iron rods. Only one of them is a magnet.
How can you identify which one is a magnet?

Many have heard it, but nobody has ever seen it, and it will not speak back until spoken to. What is it?