There are three blocks, A, B and C. Block A is to the right of block C and to the left of block B. Block A contains three medium black squares. Below medium black square number two and medium black square number three is medium black square number one. Medium black square number two is below medium black square number three. Block B contains a medium yellow square. And block C contains a medium yellow square.
Which object is to the left of a medium black square? medium black square number one or medium black square number three?
medium black square  number one medium black square  number three both of them none of them