Hm, before drawing number 3 there are 3 situations of ball combinations
8/55 ; 9/54 ; 10/53
after the draw
7/55 ; 8/54 ; 9/53 ; 10/52
where the first 3 have at least one colored ball
You have to somehow break the chance for each combination happening down.
Then you will see the systematics popping up.
Ok, I guess Im lost here too,
but Im not a math wiz, there are some math students here too,
please help out