For this problem, assume the balls in the box are numbered 1 through 8, and that an experiment consists of randomly selecting 2 balls one after another without replacement.

Question

What probability should be assigned to the event that at least one ball has
an odd number?

Answer 1

So this is the same as saying one odd ball and one even ball or two odd balls.

4/8 for first odd ball and 4/7 for even.

4/8 for first odd ball and 3/7 for second.

To find probability of both/all events occurring , multiply the probability of the individual events.

To find either-or probability, add the individual probabilities.