The Product Rule helps you to find probabilities involving intersections (and). It is easiest to apply when you have put your information on a tree diagram. This video shows how to find the probability of drawing two hearts in a row from a standard deck of cards.
For this example, you have two sets of branches since you are drawing two cards in a row.
If you are finding the probability of producing three male offspring in a row…you need three sets of branches. Each set of branches has goes toward male of female.