In your backpack there are three math books, two science books, and five notebooks. If you reach into your backpack and select a math book, and then reach in and select a notebook, are these independent events? Explain.

When you selected the math book, it was an independent event.

However, when you selected the notebook, it was a dependent event.

The math book is an independent event because it's selection doesn't depend on anything else...it's the first thing you chose.  However the notebook is a dependent event because you did not put the math book in the bag after you took it out.  Therefore, because you selected the math book first, you only had 9 items to choose from as opposed to 10 if you had put the math book back.