Final answer:
The event of picking the number 9 is a simple event because it represents a single outcome in the experiment of choosing an integer from 1 to 15.
Step-by-step explanation:
When considering the experiment of randomly picking an integer from 1 to 15, the event of "picking the number 9" is classified as a simple event. This is because a simple event is associated with a single outcome of an experiment. In this case, selecting the number 9 is one such distinct possibility among the 15 and does not involve any combination of outcomes, making it a simple event by definition.
What is a Compound Event?
A compound event, on the other hand, involves a combination of two or more simple events. For instance, picking an odd number between 1 and 15 is a compound event because it encompasses several outcomes (1, 3, 5, 7, 9, 11, 13, and 15).