What does this rebus riddle means ?

Yesterday I fell from 30 feet high ladder but I don't get hurt. Why?

It walks on 4 when its young, walks on 2 when it's older, and walks on 3 when its very old?

What is the Surname of Barbie Doll?

How many bricks does it take to complete a building that is 15 feet wide, 30 feet deep, and 12 feet tall made of brick?

There is something which you can be arrested for attempting but not for successfully completing.

I possess a head

I flaunt a tail

But I don't have mouth or legs

Can you find out who I am?

John buys rice at Rs.60/kg from Britain and then sells them at Rs.5/kg in India. As a result of this, he becomes a millionaire. How come?

Count the number of triangles in the below picture?

A Car driver was heading down a street in Washington. He went right past a stop sign without stopping, he turned left where there was a 'no left turn' sign and he went the wrong way on a one-way street. Then he went on the right side of the road past a cop car. Still, he didn't break any traffic laws. Why not?