In the first case; imagine you are an observer at a table. What is the chance that none of the 10 players you see have an A? This is the general question.

In the second case; imagine you are sitting at a table. You see your two hole cards . . . and you know you that don't have an A (so two less unknown cards). "What are the chances that the ramining 9 players don't have an A either?" is essentially the question.