10 colored balls, 55 black balls (no white balls..)

Dont remember the probability stuff anymore in detail

But if you break it down, for 2 balls, it should be:

p1=10/55
p2=9/55*p1 + 10/54*(1-p1)
p2=0.2094 = 21% chance

or?

Some small recent games of mine:
Griefer 4k http://damocles11.byethost9.com/griefer4k.html
Kobold 4k http://damocles11.byethost9.com/kobold.html
Cave 4k http://damocles11.byethost9.com/cave4k.html