Posted by Amanda on .
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.
What probability should be assigned to the event that at least one ball has
an odd number?

Math 
PsyDAG,
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 eitheror probability, add the individual probabilities.