For each choice of a sweatshirt, there are two choices for the running pants.
Example Tree Diagram:
Practice makes perfect
We want to make a tree diagram to show all possible combinations of training outfits. There are 3 choices for the sweatshirt. The white, red, and gray ones. Let's make a diagram listing these three options.
Next, for each choice of a sweatshirt she can choose a black or a gray running pants. Let's add these options to our diagram. We will also draw a line segment that connects a choice for the sweatshirt with possible choices for the running pants.
Finally, let's add a column for the sample space which lists all possible pairs of sweatshirt and running pants. Let's also draw horizontal line segments that connect a pair with the last choice of running pants. That way, we can follow the path created by segments from the choice of a sweatshirt to the resulting pair in the sample space.
