Tree Diagrams
Example 2

Suppose the machine has a "Randomize" setting that randomly chooses the speed, volume, and style. What is the probability that you will end up with a loud rock song that is not slow?

Step 1. Count the total number of favorable results.

There are two results that match the criterion:
"fast-loud-rock" and "medium-loud-rock"

Step 2. Count the total number of results.

There are 12 total results possible.

Step 3. Use the probability formula.

Prob_ex5

This means that non-slow, loud rock songs should happen 1 out of every 6 times. In other words, there is a 17% probability of any given song matching this description.