What is wrong in the below Picture?

If eleven plus two equals one, what does nine plus five equal?

Take 9 from 6, 10 from 9, 50 from 40, and leave 6.

How Come ??

Can you find a pattern and the missing number in the series given below?

100, 155, 258,? , 584, 819.

A guard is positioned at the one side of the bridge saying ‘A’. His task is to shoot all those who try to leave from ‘A’ to the other side and say ‘B’. He also need to welcome the person who comes from another side ‘B’ to his side ‘A’. The guard comes out of his post every 1 hour and looks down the bridge for any people trying to leave. You are at side ‘A’ and wish to go to another side ‘B’. you also know that it would take 1:45 hr to cross the bridge. How will you cross the bridge?

What does the below mathematical rebus mean?

It's a protector.
It sits on a bridge.
One individual can see directly through it, while others wonder what it hides.

What is it?

What 8 letter word can have a letter taken away and it still makes a word. Take another letter away and it still makes a word. Keep on doing that until you have one letter left. What is the word?

I have a head like a cat and feet like a cat, but I am not a cat. What am I?

By using 'because' continuously three times, can you make an English statement ?