The Counting Principle: Dependent and Independent Events.

What will be the difference in counting the different ways you may choose 3 big marbles, 3 medium size marbles, and 3 small marbles from a bag with 10 big marbles, 5 medium size marbles, and 7 small marbles? ... Is it important if I return any taken marble back to the bag before picking the next one? For each concept introduced or problem given as example you will have the opportunity to interact with the lesson by clicking at the pull down menu for MARKER TOOLS menu and select the pen or highlighter and use the screen space to work the problem by yourself. Scroll further below the screen to find some helpful definitions related to the lesson.

Problems like the one above, sometimes are confusing for students. This lesson tries to focus in dissipating those doubts. You will find it entertaining and valuable; since it uses a lot of visual contextual clues to show the processes involve in the task. It is worthwhile the try!

Lesson's Content

Lesson In PDF Format (no animations)


Lesson's Glossary

Counting Principle
If event X may occur in x different ways and is followed by event Y that may also occur in y ways, then the event X followed by the event Y can occur in (x)(y) different ways.

Dependent events: The outcome of a dependent event is affected by the outcome of the previous event.

Independent Events: If an outcome doesn’t affect the outcome of a following event, then the two events are independent.


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