Are you clever or............??!!then try to solve this puzzle..

hi all guys...

well...
last year my friend told me a puzzle that made me crazy........

believe me i just wanted to kill her or something...!!!!



i dont know if you heard it before....
lets see if you are clever enough to solve it...:



a man is driving a train..and he stoped on four stations:

in the 1st station.....3 persons get in..and 7 get out of the train...

in the 2nd station...11 get in...5 get out....

in the 3rd station...9 get in...and just 1 get out....

in the 4th one....6 get in..and no body get out...






the question is....















what is the name of the driver ???!!!!




yeah i know i cried too.......:S