No one wants to have it, but if one got it, he does not want to lose it. What is It?

Peter wakes up daily to pick up his cycle and crosses the border between Spain and France daily with a bag on his shoulder. He is investigated daily by the officials but they don't find anything suspicious.

If we tell you that he is smuggling something what would it be?

You are presented with three boxes. One of them has a red ball inside and the other two have a black ball inside each of them. You are asked to pick up the one with red ball and you pick one. Now, one of the other boxes is opened and it is found to have a black ball.

You are presented with a chance to change your box with the one that is left closed. Will you change your box? Why or why not?

I come in different shapes and sizes.
Parts of me are curved, other parts are straight.
You can put me anywhere you like,
but there is only one right place for me.
What am I?

In the below-given picture of a pretty girl, there is something wrong. Can you find out what it is?

Can you count the number of triangles in the given figure?

What is wrong in the below Picture?

How many letters are in the alphabet?

Why do we preferably have round manhole covers and not square ones?

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