ok. im beginning to see where I am going wrong.
the probability that A doesnt score and B doesnt concede is always 1
the probability that A doesnt score or B doesnt concede is either 1 or 0
The events are opposite sides of the same event in a way.
I need the probability that A doesnt score given that B doesnt concede, but the formula for that ( conditional probability) involves using (A and B), which I know I cant use because of the reasons above, so I am back to square one again.
Any more help?